Canon EOS Beginners FAQ
Copyright © 2002-2013 NK Guy
Version 0.9.6. 12 December 2010.
Part V - Filters.
I bought a filter. Do I have to adjust something on the camera to use it properly?
Most SLR cameras, such as all Canon EOS cameras, do their metering directly through the lens. So if you put something like a filter in front of the lens you dont need to compensate manually at all. The filter reduces the amount of light entering the camera, of course, but the camera still meters through the lens as it always would. So it works just fine.
There are at least three special case scenarios where this is not strictly true, however. None of these are typical situations encountered by a beginner, but here they are for completeness:
1) If you use a handheld light meter (a separate device from the camera) instead of the cameras built-in light meter then you will obviously need to compensate for the presence of a filter.
2) If you use a linear polarizing filter rather than a circular polarizing filter you may experience errors in the metering and autofocus system. Then again, you may not. But best play it safe - when buying a polarizing filter for your camera buy only circular polarizers, sometimes identified as CPL filters.
3) If you are doing specialized infrared photography using a black filter which blocks visible light but which lets infrared energy pass through the cameras internal meter is likely not to work very well, since camera meters are designed with visible light only in mind.
My camera salesperson tried to sell me a protective filter. Should I get one?
This is another question with a yes and no answer. There are two schools of thought regarding clear glass or UV-blocking protective filters. Some photographers use them to reduce the risk of damage to the lens - if you bash your lens against the wall then having a filter lowers the risk of the lens itself suffering damage. Other photographers refuse to use them on the grounds that any extra glass on the end of the lens, no matter how good, degrades image quality.
So there are a number of points here. First, theres nothing utterly essential about protective filters. Youre simply lowering the risk of lens damage by using one. Second, if you get a UV filter to serve as lens protection try to get the best quality you can afford and keep it assiduously clean. A cheap or dirty filter will degrade the quality of your photos dramatically. Third, remember that camera salespeople earn big commissions by selling you little accessories like this - dont necessarily buy whatever theyre trying to push on you. Chances are theyre trying to sell you a piece of junk that happens to earn them a bigger commission. Fourth, using a filter doesnt mean you dont have to use a lens hood. In fact, in the case of lenses with slightly recessed front elements, putting a filter on means youre going to run a greater risk of lens flare than without. Always use a hood.
Now, having said all this about theory, my views on using a filter on a lens changed last year somewhat. I was in Tunisia and taking some photographs in an old Roman amphitheatre. I didnt have a lens on my camera, had the hood off temporarily and somehow banged the lens against a stone column or something. The front element on the lens got badly scratched and gouged. If Id had a filter or a lens hood in place then Id still have a usable lens. As it is I havet, since getting a replacement front element from Canon is half what the lens if probably worth these days.
For more information on filters in general, have a look at my filters page.
Should I buy a coated or an uncoated filter?
Nearly all lenses sold today for 35mm SLRs are coated with optical coatings that are designed to reduce internal reflections. This is pretty critical for image quality - particularly contrast and flare. Some filters are monocoated, some are multicoated, and some arent coated at all.
The argument in favour of coatings is pretty straightforward. Youve got coated lenses - why spend money on putting uncoated glass in front of them? Regular filters mean youre putting two reflective surfaces in front of your lens. Surely you should go for the best image quality and get coatings.
The arguments against are that coated filters are harder to clean and easier to scratch. These are both demonstrably true. Fingerprints show up much more easily on coatings, and getting that fine layer of greenish shimmering finger oil off a coated surface can be a real pain. And some coatings are indeed easy to scratch.
Personally I go for multicoated filters for the most part. I buy the reduce reflections argument - Ive had a few pictures suffer from lens flare - one from a really bad internal reflection - caused by uncoated filters. As for cleaning, yes. It is a pain. But keeping your lens clean is important for image quality regardless. And I try to keep the filters in their cases when theyre not being used to minimize the chances of coating damage.
What does a polarizing filter do?
Light moves through space, vibrating as waves in many different directions. Light which is polarized, however, only vibrates in one plane. A polarizing filter or polarizer is a lens filter which polarizes light along one plane. This can cut non-metallic reflections and enhance contrast under certain conditions.
Polarizing filters contain a layer of polarizing material which is laminated between two glass circles and mounted in a frame. You can then rotate this filter, which affects the amount of light passing through. Even at their brightest setting, however, polarizing filters reduce the amount of light entering the lens - they always cost a stop or so of light.
So what use are they? Well, polarizers are useful for cutting reflections from water and glass (ie: non-metallic) surfaces. Theyre commonly used for cutting reflective glare off of windows, or for taking a photo of a lake without a reflection on the lake surface, for instance. They can also be used to darken blue sky (technically, increase the colour saturation of the sky since light scattered by Rayleigh scattering is polarized) and certain types of vegetation. The effect of a polarizer on the sky varies depending on the angle to the sun (known as Brewsters angle). So a very wide-angle lens (wider than 24mm or so) with a polarizer will demonstrate differing amounts of polarizing across the frame, which may or may not be objectionable.
There are two basic kinds of polarizers - linear and circular. Linear polarizers work well with manual focus cameras, but they interfere with autofocus cameras. Circular polarizers contain another element - a quarter wave plate - which ensures compatibility of the filter with autofocus systems. So if youve got an autofocus camera - like any EOS model - be sure to use only circular polarizing filters. Note that polarization is one of the few visual effects provided by filters which strictly speaking cant be simulated digitally in an image editing program.
What common filter sizes do Canon employ?
Like most Japanese camera makers, Canon use threaded (screw-on) filters with metric measurements on most of their lenses. The exceptions are those lenses with very large front elements that are too big to accept threaded filters - the super-wide angle lenses and the really huge telephotos. These use internal drop-in filters instead.
Canon have standardized their filters to a common set of sizes. The sizes used by Canon are typically:
- 52mm. Used on the small primes, such as the 50mm 1.8 mark 1 and the 28mm 2.8, and on some earlier consumer/midrange zoom lenses.
- 58mm. Used on the vast majority of Canons midrange zooms.
- 67mm. Fairly rare size for Canon, but being employed more frequently. Used on a few midsized zooms, both L and non L.
- 72mm. Used on a number of larger pro/midrange zooms, and a few primes.
- 77mm. The most common filter size seen on larger L series lenses.
Its convenient that Canon have relatively few filter sizes, as it means you can invest in a good selection of filters for each type of lens that you own, and minimize the number of different sizes you carry with you.
Of course, if you have infrequently used larger filters you can use step rings to adapt them to smaller lenses. So if you rarely use a red filter, for example, you might buy a 72mm one and then adapt it to your 67mm filter size lens when needed.
What is a neutral density filter?
Neutral density (ND) filters are simply filters which block a certain percentage of light from passing through. In other words, theyre darkening filters. The neutral refers to the fact that a proper ND filter does not colour the light inadvertently. (ie: a true neutral density filter does not introduce any colour casts to the image)
Such filters are useful for, for example, shooting outdoors in bright sunlight when you happen to have fast film. Theyre also handy for extending shutter times. For instance, nature photographers often like shooting waterfalls or moving water with very long shutter times in order to achieve the bridal veil effect of blurring motion. To do this with ordinary film requires an ND filter to cut back the amount of light hitting the film. Users of mirror lenses also use ND filters in the unusual case that they need to cut back on light, since mirror lenses lack adjustable aperture diaphragms.
ND filters are typically specified in either decimal values or numeric factors. 0.3 ND filters cut 2X the light entering, 0.6 ND filters cut 4x the light entering, 0.9 ND filters cut 8x the light entering, and so on.
What is a graduated neutral density filter?
A graduated neutral density filter is a specialized type of neutral density filter. Such a filter has a dark side and a clear side with a smooth transition line between the two. Such filters are useful for taking photos of scenes where one half is bright and the other less so.
For example, a classic case where GND filters are useful is that of a sunset. Light from the setting sun isnt as bright as the noonday sun but is still too bright for the range of film to accommodate. So if you meter to get the sky right then the ground or ocean portion of the photo will be wildly underexposed and look like a dark blob. But if you meter for the darker section then the sky will be completely blown out and overexposed. The answer is to use a graduated neutral density. You position the filter such that the darker section darkens (holds back) the sky and the clear section is over the non-sky areas. You then expose for the darker area and the bright area will come through beautifully.
GND filters come in varying densities and also with hard or soft transition lines. Hard lines offer a fairly sharp transition between the dark area and the clear area and are useful for sky and ocean shots, etc. Soft lines offer gradual transition and so disguise the transition better for landscapes and the like. Unfortunately there is no standard for the distance over which this transition takes place, so each filter maker has its own idea as to what is a hard or soft transition.
Is putting more than one filter onto a lens okay?
This is a practice known as stacking filters. And generally its probably not a good idea since the risk of vignetting goes up. By putting more and more filters on the end of your lens youre essentially making your camera look through a long tube. In addition each piece of glass you add has the potential to degrade image quality further.
Unless you really need to put two filters onto your lens to achieve a certain effect its probably wise to stick with just one at a time.
Do I need a slimline filter for my wide angle lens?
Wide angle lenses are more susceptible to the problem of vignetting than other types of lenses. For that reason filter makers often make low-profile or slimline filters for use with wide angle lenses. Such slim filters may lack a front filter thread, so they may require press-on lens caps rather than normal ones. They also tend to cost more.
In my experience with a number of Canon lenses you can safely put any normal filter on Canon wide-angle lenses (Ive used up to 20mm) without fear of vignetting. Obviously cheap filters with gigantic high-walled metal rings might be a problem, but typical Hoya or B+W filters havent been a problem for me. Now, your mileage may vary, as they say. So its probably wise to do a quick test if possible - take photos of the sky at different aperture settings to see if theres any darkening around the edges with and without the filter. But I wouldnt automatically assume you need to buy a costly slimline filter unless, perhaps, you like stacking filters.
I have filters which dont fit my lenses. Can they be adapted?
Yes. You need what are known as step rings - simple machined metal adapter rings which fit between the filter and the lens. Such rings are fairly inexpensive and readily available from camera shops.
If you have a large filter and want to attach it to a lens with a smaller filter diameter (eg: a 72mm filter on a lens with a 58mm filter thread) then you need a step-up ring. If you want to go from a small filter to a larger lens you need a step-down ring.
Adapting filters in this fashion often works fine but there are some points to keep in mind. First, attaching a small filter to a larger lens will usually result in vignetting - darkening around the edge of the photograph. The smaller the filter the higher the likelihood of vignetting. Second, attaching larger filters to smaller lenses often poses problems when you try to attach a lens hood. The filter might prevent the lens hood from fitting or might make it inconvenient to rotate polarizers, etc.
Naturally, the closer the filter and lens are in size the better. Using 58mm filters on 52mm lenses is rarely a problem, for example. Step rings are thus handy for minimizing the number of filters you have to carry around for a given lens set.
What are these numeric codes on my filter?
Unfortunately there is no universal specification for filter types. Luckily filter thread types are pretty well standard across all major Japanese camera makers, but filter colour and type are named on a manufacturer-specific basis.
There are two common systems in use, however. Most American and British filters are specified using Wratten numbers, an arbitrary series of numbers and letters created by UK photographer Frederick Wratten. And German and Scandinavian filters tend to be use a different system which include K (warming) and B (cooling) filters.
What about Cokin filters?
Ah, Cokin filters! Delightful rectangles of plastic sold by the millions during the heyday of amateur photography in the 1970s! No matter what cheesy effect you want - lurid pink skies, prismatic highlights, simulated motion blur - Cokin can help you! Every camera shop has a dusty rack in the corner laden with Cokin filters.
Personally I think theyre pretty expensive toys, particularly given that theyre just uncoated pieces of plastic resin. Photoshop has far surpassed Cokins ability to alter images, and it does so in a far more flexible and versatile fashion. Cokins P holder is useful as a standard filter holder compatible with wide-angle lenses (particularly if you saw off the outer two slots), though many people eschew Cokins grey graduated filters as they arent true neutral density filters and can lend subtle but unwanted colour casts. But frankly the day of these novelty filters has come and gone. Unless you still shoot exclusively on film, digital has made these filters largely irrelevant.
Why do black and white photographers use such brightly coloured filters?
Colour filters can achieve a variety of effects in black and white photography. They work by passing light thats the same colour as the filter and blocking much of the light thats the complementary colour. For example, a red filter lets lots of red light through but blocks blues and greens.
What does this do on black and white film? Well, such colour filters have the effect of brightening areas in a photo of their own colour and darkening areas of their complementary colours. So, our red filter will make a red T-shirt look almost white and a blue sky look dark grey or almost black. Its for this latter purpose that red filters are commonly used in black and white photography - they can be used to darken skies dramatically and smooth skin tones of lighter-skinned people.
This effect of sky darkening is particularly useful when there are clouds. Clouds and sky are often the same brightness on black and white film, which means that clouds can end up disappearing in the final photo. By using a red filter, however, you can darken the sky in order to heighten the contrast between the sky and clouds.
The main drawback of such colour filters is that they decrease the overall amount of light entering the camera. You dont have to adjust for this if youre using the cameras built-in light meter, but it does mean that you will need slower shutter speeds than if you didnt use the filter at all.
My pictures suck. I want to attach a magic filter to my lens to make them look great.
There is no such device.
Generally speaking, good photos tend to result from, in varying degrees, a good eye, good technique, good understanding of lighting, quality lenses, experience and luck. And you dont even necessarily need a quality lens, though they can obviously help a lot if you want to take a sharply focussed or high-contrast image.
VI - Miscellaneous questions.
The edges of my photos are dark. Whats going on?
This is a problem known as vignetting (though its technically sometimes peripheral darkening, which looks pretty well the same in the final photo), and has several possible causes.
How can I get the sharpest photos possible using my equipment?
What is the handholding rule for non-blurry photos when not using a tripod?
Taking photos with the camera mounted firmly on a tripod will always yield sharper pictures than if you were to hold the camera in your hand. No matter how steady you are youll always move slightly during even a split-second exposure. You can mitigate this somewhat through a variety of means - bracing yourself, pressing the shutter release gently rather than jabbing it, trying to lean against a wall or a fence, holding your breath or gradually exhaling as you take the photo, using an image stabilized lens, and so on. But despite all these things a tripod is a safer bet.
However, tripods are obviously a nuisance to use much of the time. And if the shutter speed of the camera is high enough then camera blur shouldnt be too bad. The question is, how high a shutter speed is fast enough?
Theres a basic rule of thumb in photography which says that you shouldnt use a shutter speed slower than the reciprocal of the focal length value. That sounds complicated, but its actually really straightforward.
Lets say youre using a 50mm lens. The reciprocal of 50 is 1/50. So you shouldnt use a shutter speed any slower than 1/50 of a second when handholding a 50mm lens. Of course, most cameras dont have a 1/50 sec setting, so you round it up to 1/60 second.
Its as simple as that. Put the value of the current focal length as the denominator of a fraction with 1 as the numerator. When using a zoom lens use whatever focal length the zoom is currently set to.
Now youll notice two important consequences of this rule. First, it means that when youre using long telephoto lenses you have to have relatively high shutter speeds. A 300mm lens, for example, requires at least a 1/300 sec exposure. Second, it means that you can get away with relatively slow shutter speeds when using a wide angle lens. A 15mm fisheye lens, for example, lets you use 1/15 second.
Of course, this rule is modified somewhat if you have image stabilization (IS) on your lens. IS lets you gain at least an additional two stops of shutter speed.
Now technically this rule of thumb is about determing the minimum shutter speed for a given field of view. By coincidence it just works out fairly well if you use the lens focal length when shooting 35mm film.
Do I really need a tripod? Theyre such a pain to haul around.
Yes, they are a pain. Good tripods in particular are heavy and clumsy to carry. But theyre often the best way to take a sharp, clear photograph by providing a stable, relatively vibration-free platform. If image sharpness is important to you - as it is for studio photography and nature photography, for example, you need a tripod. And of course theyre pretty well essential for night photography, where long exposure times (often many seconds or minutes) will cause hopelessly blurred photos if you try to handhold the shot. Try to get the heaviest one you can reasonably carry as lightweight ones vibrate too much, and consider investing in a quick-release head as the added convenience means youll probably end up using it more.
Obviously tripods arent an appropriate tool for candid or street photography where you need to move quickly, so this isnt an absolute rule. If you cant use a full-sized tripod try anything else that helps increase camera stability. For example, monopods are simple telescoping poles with camera mounts on the end. Theyre popular with some photographers as theyre quite lightweight and portable, yet stabilize the camera in one direction (vertical) and help minimize movement in the other (horizontal). Some monopods even double as high-quality hiking or trekking poles, making them useful for rugged nature photography.
Another option is a tiny folding tabletop tripod sturdy enough to support the weight of your camera and largest lens. Such tripods can be used on flat surfaces like tables and car roofs quite effectively. Some even have velcro straps so the small tripod can be strapped firmly to a tree trunk or a fence.
Other options for camera stabilization abound. Beanbags are popular accessories for shooting out of car windows or when lying on the ground. Chainpods are simply lengths of metal chain (or non-stretchy rope) attached to the tripod mount. The end of the chain dangles to the ground, allowing you step on it and pull the camera up for stability. You can even get shoulder stock mounts with triggers which let you shoot your camera as if it were a rifle, though such devices are obviously highly unwise if youre taking photos of political figures or people in public. And so on.
My camera doesnt fit my tripod. The bolt is the wrong size. What can I do?
The vast majority of cameras sold today use a 1/4-20 tripod mount socket. This means that the bolt which fits into it is 1/4 inch in diameter and has 20 threads per inch. Even European and Japanese cameras and tripods use these non-metric measurements for historical reasons. Conveniently, most tripod heads also use the 1/4-20 size.
However, some tripod heads and some larger cameras use a 3/8-16 bolt size. If you need to go from one to the other you can purchase bushings which fit into the larger hole, though for some incomprehensible reason these bushings are often sold in unhelpfully large packages, such as 25 to a pack. You can also buy adapters.
Note that since cameras use standard 1/4-20 sockets its very easy to make your own homemade camera stand or tripod mount. 1/4-20 bolts are commonly available in hardware stores (though it may take some searching if youre outside the UK and North America). However, remember that the hole itself isnt very deep. If you try to force a bolt too far into the camera body you could seriously damage your camera. Especially if your camera has a plastic tripod mount, as most low-end cameras do. For that reason you should test the length of the mounting bolt very carefully.
What is the sunny 16 rule?
The sunny 16 rule is a simple rule of thumb for taking photos in daylight without a light meter. The rule is quite easy to remember - if youre taking a photo in bright daylight set the aperture to f/16 and set the shutter speed to be as near as possible to the reciprocal (1 / x) the film speed.
So if youre using ISO 100 film, for example, you would set the aperture to f/16 and the shutter speed to 1/100 sec. However, since most cameras dont have a 1/100 sec setting you would set it to the closest shutter speed, which is 1/90 sec.
If you want to use a different aperture calculate the number of stops away from f/16 you want to use and then adjust the shutter speed accordingly. For example, f/11 is one stop larger than f/16, so youd need to decrease your shutter speed by one stop. So if youre using ISO 100 film youd set the aperture to f/11 and the shutter speed to 1/200 sec.
This rule works from many locations on the Earth because the light output from the sun is a pretty constant value - the sun itself puts out a nearly constant amount of light at all times. Only precisely calibrated equipment can detect the light fluctuations of the sun.
What is the rule of thirds?
The rule of thirds is the compositional guideline (it isnt strictly a rule per se) which states that images with dominant points of interest usually look best with those points situated about 1/3 of the way along the image.
For example according to this guideline a horizon looks best 1/3 of the way down from the top of the image or 1/3 of the way up from the bottom. Or a picture of a field with a large tree in it will look best when the tree is situated roughly 1/3 of the way across the image from one edge. Its a useful starting point for composition, especially if youre a beginning photographer. A common novice mistake is to centre everything and try to get things right in the middle, which often results in rather static-looking photos.
This guideline is essentially a simplification of the golden section or golden mean.
I took a photo and the sky is white. Why is this, when the sky was actually blue at the time?
The basic problem is this: the human eye is capable of sensing a pretty wide range of light levels. Film and digital image sensors, however, are not.
So lets say you take a photo of something and your camera meters off the foreground to expose it correctly. If theres a fairly wide range of brightness between the sky and the ground then metering for the ground will cause the sky to be vastly overexposed. And if its overexposed then itll appear blown out or pure white - its as bright as the film or sensor are capable of recording.
The same problem occurs at sunset. A common beginner experience is to take a photo of a glorious sunset and to be utterly disappointed when the picture returns from the lab. The difficulty here is similar - theres a wide range of brightness between the foreground (the ocean, beach, etc) and the sunlit sky. So you can either take two photos - one exposed for the sky and one for the ground - and glue them together digitally or you can put a graduated neutral density filter over your lens. A graduated ND filter is darkened at one side and clear at the other so you can darken the sky and still expose for the ground. Such filters obviously take a little experience to use effectively, however.
I need help! Im shooting a wedding this weekend. What film and lens should I use?
Okay. The usual response to this type of question is as follows: if youre asking such basic questions then you shouldnt be taking photos of a wedding if youre supposed to be the photographer of record. Find a professional right now.
If youre just going to the wedding as a guest and you want to take some snapshots, and the wedding party are relying on someone else for the main photos, then sure. Grab a fast zoom lens and a flash with a diffuser or flash bracket, and have fun.
Why is this the usual response? Isnt it kind of elitist? Well, people tend to place a massive amount of emotional importance upon their wedding pictures. A given wedding is a one-off event. You cant go and get everybody back in the church or synagogue or temple or garden and do some retakes if you screw up. People expect a certain level of production value from other peoples wedding pictures and will likely be rather disappointed by ho-hum pictures. And a sure-fire way to damage a friendship or family relationship is to mess up someones wedding photos badly.
Of course, hiring a professional is by no means a guarantee of anything. There are tons of lousy pro wedding photographers out there who are incompetent or who overcharge or whatever. But at the very least if someone else does the photography you arent risking your friendship or relationship.
Now, having said all this, thats the usual advice. And you dont have to follow it by any means. I didnt and managed to pull off some okay (but sadly not brilliant) wedding shots as an amateur. It was a combination of doing a lot of testing at the venue beforehand with different film and flash settings (and careful note-taking), renting professional-quality gear, and blind luck. And boy, was it stressful! I also took the photos at my own wedding, but thats another story altogether. (yes, Im still married)
Is it true that taking a persons photograph steals their soul?
Yes. This is why movie stars, fashion models, politicians and pop singers have such dreadful personality and relationship problems - their souls have been severely depleted by all the photographs which have been taken of them.
Why are Canon EOS digital cameras so expensive?
Very simply, its because it costs more to build a digital camera than a film camera given todays technology. And the base level of features of today’s consumer digital EOS cameras exceeds high end advanced amateur cameras of the film days. The bar has been raised.
Canon have produced a number of digital cameras compatible with the EOS system over the years. The first generation of these cameras was built in conjunction with Kodak. They were modified Canon EOS film camera bodies (the top of the line 1N) with film transport components taken out and Kodak-designed digital equipment stuffed inside the body and its add-on grip. This DCS series of cameras - the DCS3, DCS1, D2000 and D6000 - was mainly aimed at professional photographers who needed to be able to send photographs from the field rapidly and were at the cutting edge of digital photography at the time. They were thus very expensive - the 1.3 megapixel DCS3, for example, listed at over $15,000 US when it came out. Today you get better resolution than that (though not better lenses, admittedly) in ordinary mobile phones.
The subsequent generations of Canons EOS digital cameras were and are wholly built and designed by Canon and are digital cameras from the ground up - they arent retrofitted film bodies like their predecessors. Unlike digital point and shoots the new EOS digitals are all fully compatible with the EOS line of lenses and accessories and offer excellent image quality. But they too are considerably more expensive than point and shoot digital cameras.
Why is this? Well, there are many reasons involving R&D costs, high market demand and so on, but a significant factor is the cost of making large digital image sensors. Point and shoot digital cameras all have really tiny image sensors which are quite cheap to produce. Digital EOS cameras, by comparison, use much larger image sensors, from the full-sized 24x36mm sensor of the EOS 1Ds and 5D mark II to the smaller APS-sized sensors used in the other cameras.
Still, prices are falling rapidly and used digital cameras can be had today for a fraction of what they cost new.
Why doesnt the back screen on my EOS digital camera display a live video preview?
Your camera is an older or lower-end EOS digital camera, which lacks support for Live View video.
Unlike point and shoot digital cameras, Canon EOS digital cameras are SLRs, which means they use mirrors. The image sensor is situated behind the mirror, so no light reaches the image sensor normally but is instead deflected up into the viewfinder. When a picture is taken the mirror flips up out of the way, blacking out the viewfinder and letting light reach the image sensor. Using this design means there is traditionally no way to have live image previews on the rear screen of the camera and have a working optical viewfinder at the same time, since the mirror is normally down and blocking the light path to the image sensor.
Accordingly, Live View cameras have a video mode which flips up the mirror and feeds live video to the rear LCD. This means, of course, that the viewfinder is blacked out when Live View is on. It also means that the camera has to be able to transfer a massive amount of data from the sensor chip to the memory card in realtime, something which simply wasn’t technically possible with the first models of EOS digital cameras.
The first EOS camera to support a form of Live View was the limited edition EOS 20Da, intended for astrophotography. It flipped up the mirror and permitted a preview, but it only worked in low light levels and you couldnt meter or autofocus when the mirrors up, so it wasnt remotely useful for the casual photographer. The later generation of EOS cameras from the late 2000s support Live View properly, and can mostly also capture live video as well.
Why are the pictures from my digital camera soft-looking?
Digital EOS cameras assume youre going to be applying sharpening filters to the images once they arrive on your personal computer. In other words they dont do much by the way of sharpening inside the camera so as to give you lots of control over the image.
So all you need to do is to apply a little sharpening (eg: unsharp mask) to your pictures and they should look quite sharp and crisp.
What is firmware?
Modern digital cameras are actually complex computers equipped with light sensors and lenses. Like any computer, they need software to run.
Personal computers normally use well-known operating systems, such as Microsoft Windows, Apple Mac OS X, or Linux. When you turn such a computer on you have to wait a minute or so for this operating system to load and start up.
Digital cameras aren't that different conceptually, except that this startup process is hidden from the user and is normally very fast. The operating system of the camera is written by the camera maker, and is built into the camera at time of manufacture.
In the case of cheap digital cameras, the necessary software is permanently built into the camera and cannot be altered. It’s therefore known as “firmware” because it’s software that's recorded in a permanent and unalterable form.
However, EOS cameras don’t have permanent unalterable programs. Instead, they have firmware that’s recorded to special “flash” memory chips that can be updated if necessary. (though on different chips than the memory cards used to record photographs) This permits Canon to release updated versions of a given camera’s firmware in order to fix problems or, on occasion, add new features. In this context, the term firmware is a bit inaccurate, but sticks today nonetheless.
Film-based EOS cameras all contain firmware for their little computers, but it was extremely rare for Canon to release updates to these programs. They also weren’t customer-updatable. If you wanted to upgrade the firmware on your film EOS camera you had to take your camera to a repair facility.
By contrast, digital EOS cameras contain firmware that’s easily updated by the user. Whenever Canon chooses to release an update you just download a file from the Internet, put it onto a memory card, and tell the camera to update or “reflash” its firmware.
Normally firmware updates fix bugs with the camera. For example, as initially released the EOS 60D would occasionally overexpose photos when flash was used. Canon soon produced a firmware fix to the problem. But sometimes Canon actually add new features to an existing camera. For example, the EOS 5D II had limited video capabilities when it was first released. In response to the tremendous interest in DSLR video, Canon subsequently released updated firmware for that camera that permitted manual control over audio and added 24 fps shooting. This was an exciting development as photographers in the field could improve the functionality of their cameras for free.
Some enterprising hobbyists have used this firmware-upgrading facility to write their own software to control certain Canon cameras. This allows for people to add all kinds of interesting functions to their camera bodies, often well beyond what Canon designed the cameras to do.
What are RAW and DNG and why is there a controversy about them?
Film cameras output information in a fairly accessible and universal format. You have a transparent piece of film negative and thats it. You can store the negative and retrieve the image any time you like using standard equipment.
Digital photography is very different, since images are captured using computers and stored as computer files. The problem is - what format should be used for the file? Just as word processing documents can be stored in a variety of different and incompatible formats, (plain text, RTF, Microsoft Word, Wordperfect, Wordstar, HTML, etc, etc) digital pictures have to be stored in a file format.
JPEG is the most common format used for storing digital pictures. Its an open standard, meaning no one company has total control over it, and it efficiently compresses files to keep them small. (strictly speaking JPEG - the for Joint Photographic Experts Group - refers to the compression method and JFIF - JPEG File Interchange Format - the file format, but thats getting obscurely technical, since everybody lazily refers to the files as JPEG files)
The problem with JPEG is that it does not store all the information gathered by the camera. It compresses the image in a lossy fashion, which means it discards picture information that people are unlikely to notice. Thats great for minimizing storage requirements, but the drawback is that a serious photographer isnt going to be very keen on losing picture quality even to save space.
So most decent digital cameras also store pictures in RAW format or something similar. RAW isnt an acronym, but simply refers to the raw, largely unmodified data sent straight from the cameras image sensor. This is often referred to as a digital negative since its the most basic and primal way that digital picture information can be stored.
The problem with RAW is that it isnt a universally defined format of any kind the way JPEG is. Each camera outputs picture data in its own unique way. Camera manufacturers have generally not been interested in adopting any form of common standard - in fact, RAW image formats frequently vary from model to model from the same manufacturer! You then need to use the software supplied by the camera maker to transform the RAW image data into a more universally useful format, such as JPEG or TIFF.
Unfortunately most proprietary software made by camera makers has tended to be sluggish and inefficient to use, particularly in a professional context. So third party applications have stepped in to provide more useful file conversion utilities to the digital photography market. Adobes Camera RAW, Phase Ones Capture One and Bibble are the most common third-party RAW processing programs. Having such programs works well, though of course it does represent an added expense to digital photographers.
The controversy here is twofold. First, as noted, camera makers keep releasing new cameras with new RAW formats, and the makers of third party programs keep having to update their applications. For example, Canon have variously used CRW, TIF (though customized) and .CR2 files; all of which are incompatible with each other and require updated image viewer and converter programs. This lack of openness is troubling. What happens if you decide to take a look at some of your photographs in 20 years and find that there is no longer any image processing software for it? All of a sudden your pictures are gone and useless. Meanwhile you can still take that shoebox off the shelf and rescan your film negatives all you like.
And second, and even more problematic, at least one camera maker has taken steps to block access to their internal file format. In 2005 Nikon introduced the D2X digital camera, which brought with it encrypted white balance data. What this means is that Nikon deliberately lock away white balance information for no reason other than to prevent other applications from opening the files. This is a step beyond the usual practice of camera makers arbitrarily altering lookup matrices for colour and white balance data and so on from camera model to camera model.
From a technical perspective theres nothing to prevent someone else from cracking the encryption and providing software to open these files. But legislation in a number of countries - most notably the Digital Millennium Copyright Act in the United States - may make it illegal to do so. So most third party RAW readers dont have the ability to open these files because their developers dont want to be held legally liable for a violation of the DMCA. Therefore laws which were designed to shield large Hollywood studios and record labels from losses incurred by movie and music piracy are also preventing individuals from legitimately using the files that they legally own.
Adobe have created a fairly open standard for storing digital camera data, DNG (digital negative) which addresses some of these concerns, though it does permit manufacturers to store proprietary data and so does not entirely eliminate the concerns of many photographers. Unfortunately DNG has yet to gain much support from the major camera manufacturers. Hasselblad and Leica are the only camera makers thus far to give their support to the format. The groundwork has been set, however, in that most major image viewing applications now support DNG.
A group of photographers and interested users have formed a group, OpenRAW, to promote open standards for digital RAW files. If youre interested in this issue you should probably take a look at their Web site.
What's the difference between CF and SD memory cards?
Some of Canon’s EOS cameras employ CompactFlash (CF) memory cards, and some use Secure Digital (SD) cards. A number can use both. So, what's the difference and why are both card formats used? The answer is a complex mix of history and technical requirements.
To start, both CF and SD are storage cards containing “flash memory.” This means they contain small computer chips which can be erased and reused. The chips store data even when they’re not connected to a power source, so they’re sometimes called “non-volatile” memory. The differences between the two types are related to the physical size and shape of the cards and the electronics they contain.
CF is the older standard. The cards are small rectangular devices, about the size of a matchbook. They come in two physical sizes - type I and type II; the latter being thicker than the former. However, type II cards are essentially obsolete today - they were used for tiny mechanical hard drives known as MicroDrives. All CF cards have a small row of tiny holes on one edge which plug into a pin-equipped connector within the camera. This connection method is a little vulnerable to damage. If a card is jammed into a camera at a wrong angle, or if there's debris in the holes, then permanent damage can occur to the delicate pins inside the camera.
CompactFlash cards are bigger than SD, so they’ve always had the edge in terms of capacity and speed - it’s simply easier for manufacturers to cram the latest electronics into them. This has meant that they’re the preferred card for professional users, who can be assured that they’re getting the best performance available for the day. More recent developments, such as UDMA transfer capabilities, mean that CF cards continue to be very rapid at transferring data. Most professional photographers have a big investment in large numbers of CF cards.
CF cards are also quite intercompatible. Any CF card of years gone by will work in a modern CF-card equipped camera. The only real compatibility issue is that cards bigger than 2 GB in size might not have their full capacity available to older cameras.
By contrast, SD is a newer format, designed for compactness. The cards are about half the size of CF cards in area, but much much thinner. Instead of pins and holes they have a less fragile set of contacts on the back side.
Because SD cards are so small, they’ve become quite popular with makers of compact cameras. In fact, SD cards have become the most common memory card used on digital cameras today, rendering countless other types of cards effectively obsolete.
In the past it was always a guarantee that a given maker’s CF cards would always be faster and more capacious than the equivalent SD card, but that gap is narrowing and today huge and fast SD cards are commonly available.
Over time the SD card standard has evolved, with the biggest change being the introduction of SDHC (high capacity) cards, and the minor variant SDXC. This has caused some problems in the market, in that SDHC cards cannot be read by older cameras, even though they look identical to SD cards.
CF, SD, and EOS
Canon initially standardized on CF cards for the EOS camera lineup. With time they introduced dual-slot 1D and 1Ds series cameras which can use either CF or SD, or indeed both. And finally they standardized on SD for the consumer (low-end) EOS camera lineup.
Can my choice of memory card affect picture quality?
No. Digital cameras record binary data. A given bit of data is either true or it is false. Memory cards either work reliably under ordinary conditions or they dont. The only points to consider between one card and another are speed of read and write access and overall reliability of the product.
Is it true that flash memory used in memory cards wears out?
Yes. The memory cells that make up flash memory cards, used in nearly all digital cameras today, do indeed have a finite lifespan. Estimates vary from product to product, and manufacturers tend not to want to talk about it, but each cell can be erased and reused anywhere from 10,000 to a million times before internal insulators start wearing out and errors start creeping in.
Does that matter? Well, for the average user, no. Even the low estimate - 10,000 times - is quite a few rounds of photography on a card. And better memory cards contain special controllers which evenly distribute which sections of a card are used in order to minimize wear.
The finite lifespan might, however, be a factor for intensive use, particularly with older memory cards. Some card manufacturers promise replacement guarantees of 1 to 5 years, but of course getting a corrupt memory card replaced for free does little to resurrect any valuable photographs which may have been lost. Still, all things considered, flash memory seems to be a pretty reliable and stable form of data storage. This is particularly the case when you compare flash memory to its main competitor - hard disk drives - which are susceptible to shock and vibration.
A related factor is how long flash memory can retain data without power. This is particularly difficult to pin down, but Ive heard figures of around 10 years. So if, in the distant future, your grandchildren discover a box of your old memory cards its possible that any data on it will be long gone. That is, of course, assuming that they could find a way of reading the cards. That will probably be as difficult as getting 126 cartridge film printed today.
Can my digital camera shoot black and white or multiple-exposure images?
Not all digital EOS cameras are capable of these effects in-camera. This is because users of digital EOS cameras typically use a personal computer for post processing, and apply the necessary filters and effects after capturing to achieve such effects on the computer, not in the camera. However, EOS digital cameras introduced after the EOS 350D/Digital Rebel X/Kiss N Digital do have the ability to apply simulated colour filters to capture a black and white image. Canon have not, however, seen any reason to build multiple exposure capability into EOS cameras.
If you havent got one of these cameras, both of these effects are easily accomplished with image editing software. In fact, many image cataloguing programs include the ability to convert an image to black and white at the touch of a button. And you have far greater control and flexibility over a multiple exposure image in Photoshop than you do in-camera.
Desaturated colour digital photos dont look quite the same as black and white film-based photos. Why not?
Black and white film is not equally sensitive to all colours across the spectrum. Different films have different spectral sensitivities (ie: respond more to some colours than others), and experienced black and white photographers are very familiar with the tonal qualities of such films and papers.
For that reason taking a colour picture and removing all the colour information (ie: desaturating it) will not yield exactly the same results as using actual photographic film and paper. The differences are subtle but noticeable to the experienced eye. You can, however, simulate the effect of using traditional black and white film by desaturating colour channels independently in Photoshop or some other image editing program. There are also third-party plugin modules offered by various small software developers which can achieve this effect as well. And, as noted above, some later EOS bodies can also apply colour filters algorithmically to achieve traditional black and white effects.
What is aliasing and anti-aliasing?
Digital images are made by displaying tiny dots on a (usually) rectilinear grid. Straight lines which go in either horizontal or vertical directions on this grid will always look fine, but diagonal lines can be a problem. Since such lines essentially cut across the grid pattern they can appear as rough jagged stair-step lines rather than smooth diagonal lines.
There are three common ways of reducing this effect. First, if the resolution of the image is high enough (ie: each individual pixel is small enough) then the aliasing will not be readily apparent to the human eye. Second, the jagged lines can be smoothed out by filling in the stairsteps with intermediate (eg: grey rather than black and white) values. Computer software that performs this function is commonly known as an anti-aliasing algorithm. Third, most digital cameras contain optical filters situated between the lens and the image sensor which smooth out the jaggies optically before its recorded by the sensor. Such anti-aliasing filters soften the image somewhat, so you lose a little sharpness, but the reduced aliasing is generally considered to be worth it.
What does interpolated resolution mean?
Its a fancy way of saying faking it. Lets say a scanner is capable of scanning 300 pixels per linear inch. Wouldnt it be great if you could say its capable of producing 1200 interpolated pixels per inch? Well, thats what scanner makers do! They take the 300 ppi data, quadruple it and then mathematically smooth it all out. No information is added to the original scan, but the image can (depending on the sophistication of the software algorithms used) look much better nonetheless since jagged aliasing lines can often be minimized.
Does it look as good as a true 1200 ppi scan? Nope. Could you take your 300 ppi scan and enlarge it in Photoshop using Photoshops bicubic interpolation software and get pretty well the same results? Yep.
What is a digital lens?
That depends on what is meant by digital. There are three main ways in which the term digital is applied to lenses.
1) The most common use by far is stupid marketing. Digital is one of those words, like professional, next-generation, natural, multimedia, advanced, and so on, which may have a pretty specific meaning in some ways but which is tagged onto a wide range of disparate products just to make them sound desirable. I mean, whats particularly digital about a tripod? A camera bag? The word has been stripped of any real meaning in these cases. Its a hollow buzzword of the day.
2) Second, and more meaningfully, the lens could have a focal range thats useful for digital cameras with subframe (ie: smaller than equivalent film) sensors. For example, a lens with a focal length range of 24-85mm, when used on a subframe sensor digital camera, might have roughly the same field of view as a 38-135mm lens on a 35mm film camera. In this case the camera marketers might want to emphasize the usefulness of the lens for subframe cameras by dubbing it digital.
3) Third, the lens might genuinely possess optical characteristics intended for use with the current generation of digital cameras. The most common way in which it could be thus designed would be to have a reduced image circle since most digital cameras have small sensors that dont benefit from larger image circles. The EF-S lenses are an example of this. Some lenses also attempt to produce more collimated light (make the light rays as parallel as possible). Film is fairly responsive to light hitting its surface even off the perpendicular, as is often the case with wide angle lenses towards the edges of the frame. But digital image sensors dont fare as well - they work best when the light striking the sensor is precisely perpendicular to the image plane. Imagine the sensor being placed at the bottom of a shallow well - light is more likely to strike the sensor and not the well walls if the beam is perpendicular. So a lens which tries to keep light striking the image sensor in a fairly perpendicular orientation across the whole image area may indeed be better suited to a digital camera than a regular lens. Assuming, of course, that the optical gymnastics required to collimate the light dont degrade other aspects of the lens performance.
So. In the first case the term is meaningless marketing nonsense. In the second case the lens is just a regular lens that might offer certain advantages when used with digital cameras. And in the third case there are genuine reasons why the lens might be particularly suited or (in the case of lenses with reduced image circles) only compatible with certain digital cameras.
At present Canon are not marketing any of their current lenses as digital products - even the EF-S lenses - though some third parties are. Canon do claim, however, that some of their newer lenses have optical coatings optimized for digital sensors. This means that the lens coatings are supposed to reduce the risk of internal reflections off the sensor surface.
What is Err 99 on my digital EOS camera?
This error condition is analogous to the bC error with film cameras. Its most likely caused by using an incompatible lens or dirty lens contacts.
Try a different lens and see if the camera works normally. Many older Sigma lenses in particular do not work with digital EOS cameras. Try also lightly cleaning the lens and camera metal contacts - this frequently clears up the condition. Sometimes rubbing the contacts with a cotton bud can do the trick. (avoid abrasive materials such as pencil erasers) If you have a Canon lens which generates this error and cleaning does nothing then you may need to send it back to Canon for servicing. Its possible the lens mount needs some adjusting if the lens contacts dont reliably touch those on the camera body.
What is front focussing and whats this about the EOS 10D having this problem?
Ideally when you use your camera to autofocus on something the item youre focussing on should be sharply in focus. Simple enough. But if the camera consistently and erroneously brings the plane of focus ahead of the film surface (or image sensor surface on a digital camera) then youve got a problem, since everything will look slightly out of focus.
Unfortunately it appears that many samples of the EOS 10D digital camera have this problem. Not all do, and many cameras which seem not to be producing sharp results are probably not being used correctly. But some do. For more information on the problem and a simple way to test for it have a look at this Photo.net article by Bob Atkins.
Why does my EOS 300D/Digital Rebel/Kiss Digital rattle when I move it?
The metal struts which hold the popup flash on this camera are sort of loosely mounted and do rattle when the camera is moved. This is normal for this model.
How can I turn off the shutter noise on my Canon digital EOS camera?
You cant. The sound you hear is the real thing. All Canon digital EOS cameras contain moving parts which click and clack when you take a photograph. They arent like mobile phones and consumer cameras which play simulated shutter release noises through tiny loudspeakers so that people know when the camera has taken a photo.
There are two components which make up the characteristic sound of an SLR in operation. One is the clack of the mirror flipping up to allow light through to the surface of the film or image sensor. The other is the click of the shutter opening, to time precisely the exposure of the film or sensor.
All Canon digital EOS cameras to date contain electromechanical shutters, just like film cameras. The only digital EOS camera with a digital shutter is the EOS 1D, which uses a CCD chip and not a CMOS chip for its image sensor. However, even the 1D has a moving shutter, since its there in part to protect the image sensor - an important thing for a camera with a removable lens. According to Canon the 1Ds shutter is also used in bulb exposures.
What is noise?
Noise has two basic meanings in the context of photography. First, theres the obvious meaning of sound - acoustic noise heard by the human ear - mechanical shutter clicks and so on. Second, theres electrical noise. All digital image sensors are subject, to varying degrees, to this second type of noise. This is essentially the result of individual transistors in the sensor chip erroneously saying they can detect light when there actually isnt any, and adding spurious dots to an image.
In communications theory, noise is any disturbance which disrupts or affects or interferes with a signal in an unwanted fashion. In other words, the devices are actually responding to unwanted electrical fluctuations in their components, in much the same way that you can hear a hiss in telephone conversations or tape recordings. (hence the term electrical noise - its a term stemming from research into audio recordings, telephony and radio) Sometimes the noise actually originates from electricity flowing through the cameras components and is thus intrinsic and unavoidable. Other times the noise originates from external sources of interference, such as radio transmitters and other electrical devices, and can be reduced by metal shielding.
Noise appears in a digital photograph as a sort of random texture of dots. Imagine the snow on an old-style TV set and imagine that snow being superimposed over top of a picture. Unlike film grain, which can have an intriguing texture of its own, digital noise generally doesnt look very good, and camera makers go to great lengths to minimize it. Noise in a digital camera is related to image sensor sensitivity. At a simulated ISO 100 setting most digital cameras display little if any noise, but at ISO 800 or 1600 most cameras have noticeable noise. Fortunately Canon have been quite successful in minimizing digital noise over time. Earliest EOS cameras are like any digital camera and are very noisy at high ISO settings. But the most recent models are considerably less noisy. Another factor is sensor size. Cameras with larger sensors, such as full-frame sensors, are usually less noisy than a subframe sensor of the same generation. This is because the larger sensors usually have larger light-collecting areas which require less amplification.
Theres a small irregular black blob on all my pictures. What is it?
Dust on the sensor. Unlike film cameras, which expose a fresh chunk of clean film every time you wind the camera, digital cameras use the same glass sensors. And naturally dust on the sensor will appear in the same spot on every single photo you take.
This problem will be more apparent if you shoot at a small aperture (larger f/ number) than if you shoot wide open (smaller f/ number). So sometimes shooting at a wider aperture setting will minimize the problem.
But fundamentally you need to clean the sensor. And this becomes problematic, because the sensors are quite fragile and easily scratched. You dont want to be sticking paintbrushes or cotton swabs or whatever in your camera and wrecking the image sensor. Pressurized air bottles (technically gas under pressure, not air) also tend to leave residue, and are best avoided.
Canon themselves recommend to use nothing more than a squeezy rubber blower brush to remove dust, but that doesnt always do it. A lot of people recommend special sensor swabs, assembled in cleanroom situations, for cleaning the sensors. These are usually dipped in pure alcohol. But if you dont want to risk messing around that way youll need to take the camera to an authorized repair shop for cleaning.
And as for the source of the dust, its best to try and avoid changing lenses outside when its windy, or in dusty situations. Try as much as possible to change lenses under circumstances which will minimize the junk building up on the sensor.
What is dark noise subtraction/long exposure noise reduction?
Dark noise subtraction is a method for reducing noise in long exposures. First, the camera takes a photograph without the shutter open for the duration of the real exposure. This gives a map, as it were, of noisy pixels. Then the camera opens the shutter and takes the actual photograph. Once the photo has been taken the camera subtracts any noise present in the dark frame. Since both frames are taken under very similar conditions within moments of each other this is a reasonably successful technique of minimizing, but not eliminating, noise.
Dark noise subtraction thus reduces noise from long exposures - typically night-time photography - at the cost of doubling exposure time and thus halving battery life. Some EOS digital cameras can use this technique automatically to reduce digital noise in exposures longer than a second or two. If your camera lacks this feature you can do it yourself manually using image editing software. A lot of amateur astronomers apply dark noise subtraction techniques manually, using image editing software, to achieve surprisingly good photos of the night sky from inexpensive consumer cameras.
What is the EOS 20Da?
The EOS 20Da is an extremely unusual digital camera intended for a very small target market. Essentially the 20Da is a regular EOS 20D digital camera which has been modified to suit the needs of astrophotographers - people who like taking pictures of the night skies. Originally announced for the Japanese market only, the 20Da is available worldwide but only through specialized dealers and only for a limited time. The modifications are somewhat arcane, but for completeness they are:
1) The low-pass (infrared) filter has been altered to increase the transmission of 656nm wavelength light. This wavelength is also known as the Hydrogen Alpha wavelength, and improving the cameras sensitivity to this type of light means its better for taking photos of diffuse reddish nebulae. Wow. Sadly it appears that this modification does not make the camera much better for taking regular infrared pictures. It also means that you can get slight reddish tints to photos taken in daylight when using the camera normally.
2) The camera is the first EOS digital SLR to permit a live image preview by locking up the mirror. You can magnify the image preview and output it to video. Unfortunately this feature is only useful at low light levels, so it wont help you take photos during the day. Making it even less convenient is the fact that you cant focus or meter during a live video preview, and you cant use any USM lens which uses an electronic manual focus system, such as many longer L series telephotos.
What is film grain?
A photograph may appear to be made up of smooth continuous tones but close examination of film or paper with a magnifying glass or microscope reveals a different story. The images on film and paper are recorded as tiny microscopic dots, dots scattered in a diffuse pattern across the emulsion surface. The larger the dot the darker it is, so many large dots indicates a dark area and smaller dots a light area. Unlike computer graphic pixels, film grain is not in a regular linear grid.
A picture with pronounced grain at normal viewing distance is very grainy. Highly obvious grain can be caused by processing problems, or can be simply an inherent property of the film. Generally speaking, slow film (film which does not react rapidly to light) has finer grain than fast film (film which reacts rapidly to light) - see the section below on film speed. Enlarging a picture will also enlarge the grain. Sometimes visible film grain is considered an undesirable thing, and photographers go to great lengths to use slow film to minimize its appearance. Other times photographers may deliberately use fast film and certain chemical processes in order to enhance visible grain. It all depends on the type of look youre trying to achieve.
What is film speed (ISO)?
Film reacts at different speeds when exposed to light. Slow film takes a relatively long time to respond to light and so requires longer exposure times or wider lens apertures or both. Fast film is more sensitive - it reacts relatively quickly and so requires less light. Film speed is thus a measure of film sensitivity.
Film speed is rated according to standards maintained by the International Organisation for Standardisation, confusingly known as ISO (not IOS). (old-timers may recall older film speed standards, such as ASA and DIN) These film speeds run from small numbers to large, with small numbers indicating slow film and large numbers indicating fast film. Here is a list of common film speeds, with boldface speeds being the most common.
64 100 160 200 400 640 800 1600
The advantages of fast film are obvious. You can use them at lower light levels without flash, you can get faster shutter speeds, particularly with longer telephoto lenses, and so on. So why use slower film at all?
Well the primary reason is quality. Slower film typically has smaller and finer grain size (see previous question). Faster film is faster in large part because the silver halide grains are physically much larger. Unfortunately this mean that faster film is also more obviously grainy than slow. Technological advances over the past few decades mean that fast film available today usually has much finer grain than film of the past, but its still the case that, all other things being equal, slower films have a quality edge.
Digital EOS cameras have adjustable light sensitivity thats calibrated to mimic the traditional ISO scale. Interestingly enough, digital cameras have similar issues to film when it comes to light sensitivity. Generally speaking, the faster the ISO setting on a digital camera the more digital noise you get in the final photo.
What do film codes like EI 100/21° mean?
These codes refer to the film speed of the film. EI stands for exposure index, the first number is the old American ASA or modern international ISO film speed, and the second number is the German DIN film speed. Confusingly, the degree symbol refers to the DIN film speed and not to temperature.
So in this case EI 100/21° refers to what everybody calls ISO 100 film.
Note that this explanation is a vast oversimplification of the ISO film speed system, which has a complex backstory owing to political and technical reasons. Its just easiest to think of EI 100/21° as ISO 100, since thats the film speed labelling system that all modern cameras use these days.
What are C-41 and E-6?
C-41 is the code assigned to the most common colour print film processing system used for 35mm film today. E-6 is the code assigned to the most common slide (reversal) film processing system used today, developed for Kodaks Ektachrome product line.
While both processes were originally developed by Kodak, most other film manufacturers support the same C-41 and E-6 processes. That is to say, each manufacturers product has a different chemical composition and colour/contrast attributes, but nonetheless the same chemical processing systems can be used on all compatible films.
What is DX?
DX coding is how modern 35mm cameras know automatically what film speed setting to use for each roll of film. Before the introduction of DX coding in the 1980s you had to set the film speed for each roll yourself, and it was easy to forget to change the camera setting when loading film.
DX is a loose acronym for data eXchange, and refers to the series of black and silver squares on the side of most 35mm film canisters. These squares are a code, readable by most 35mm cameras including all EOS cameras, which tell the camera what film speed to use. The camera body contains a series of gold or silver pins in the film cavity which reads the code via simple electrical conductivity. (ie: black paint does not conduct electricity and bare metal does)
All EOS film cameras have manual ISO controls so you can override the automatic DX film speed setting if you prefer. These manual controls can also be used to set the film speed for those few film canisters which lack DX codes. Infrared film and handloaded film in plastic canisters, for example, usually lack DX coding.
What is film latitude?
Latitude refers to the exposure tolerance of a photosensitive material.
Narrow latitude film, such as slide film and infrared film, has a very narrow range - your exposure has to be pretty well spot on for the image to be exposed accurately. Colour print film, by contrast, has very wide or forgiving latitude, which means that exposure requirements are somewhat less rigorous - you should still be able to get a printable picture from the negative even if the camera was set a stop or two out from the desired exposure setting.
What is infrared film?
Ordinary film is capable of recording the visible light spectrum. However, theres a lot of energy (specifically, electromagnetic radiation) out there at other wavelengths which our eyes cannot see. Ultraviolet (UV) and infrared (IR) energy are both forms of energy that are invisible to us.
Infrared film is thus film capable of recording a portion of the infrared spectrum. There are different types of IR film with different technical specifications - some can see further into the infrared spectrum than others. The most commonly used types of infrared film include Rollei IR400, Konica 750 and Ilford SFX. Kodak HIE and Kodak EIR (colour slide) film was once popular, but is now discontinued.
Note that, contrary to popular misconception, infrared film is not really capable of detecting heat. Infrared photography is not the same thing as thermal imaging. Heat energy involves a different part of the spectrum - a section to which IR film is not sensitive. So you cant put IR film into your camera and see heat-loss patterns on a house or see someones body underneath their clothes or anything exciting like that. Sorry. For more information on this and other popular myths please have a look at my Infrared Myths article.
IR photography does, however, let you see the world in strange and unusual ways. Deciduous leaves, for example, reflect a lot of IR energy and so glow a beautiful white on black and white IR film. Clear (non-cloudy or non-hazy) skies are jet black. Colour infrared film results in strange and bizarre colour shifts. Theres a surreal quality to IR photography that many people find very intriguing.
Unfortunately most Canon EOS film cameras contain small internal light-emitting diodes (LEDs) which produce IR energy. These LEDs are used for counting film sprockets as part of the motordrive mechanism, but have the unfortunate side-effect of fogging the edge of high-speed (Kodak HIE and Kodak EIR) infrared film. For more information on this problem have a look at my EOS and IR article.
Note that most digital cameras can also be used for infrared photography if light-blocking and infrared-passing filters are installed. However, nearly all digital cameras sold today, including the current Canon EOS lineup, include infrared-blocking filters as part of the image sensor assembly to keep reddish IR fringing to a minimum. This means that they can be used for IR photography, but only with inconveniently long shutter speeds. The cameras can, of course, be modified but at the cost of lowered quality for regular light photography.
I have some expired film. Can I use it?
Film, like milk, doesnt instantly drop dead the moment the expiry date arrives. Especially if the film has been stored in low temperature, low humidity environments.
Theres no harm at all in using older film, assuming its not decades old, say. Even if the film has an ancient expiry date youll probably just notice more grain and worse contrast than usual.
Should I buy professional film?
Depends on your photographic priorities and goals. If youre taking snapshots of friends in restaurants, using inexpensive lenses and on-camera flash and developing the prints in a drugstore minilab, you probably wont notice much difference. But if youre going for more composed photos using slightly better gear then it may well be worth it.
The most noticeable thing is that cheap consumer film of the supermarket variety has inconsistent colour and tends to be of high contrast. Film manufacturers seem to think that consumers spend most of their time taking photos of clowns and balloons and optimize their film to produce extremely vivid and bright colour. Which is fine if you are, in fact, taking pictures of clowns and balloons. But high-contrast film isnt so great for portraiture, for example. It tends to make people with lighter coloured skin rather ruddy looking in the cheeks, etc. Cheap film also tends to sit around in shops for long periods, often in warm locations, and that all accelerates film ageing.
For that reason it may well be worth it to pick up some decent pro film. Fujis NP series (NPS - ISO 160, NPH - ISO 400 and NPZ - ISO 800) is popular colour print film, as is Kodaks Portra series. Both lines are popular with wedding photographers because their lower contrast and smooth tonality make taking wedding photos (often with high contrast blacks and whites) easier. If you want higher contrast but pro-level sharpness, Fujis Velvia slide film is popular with many nature photographers.
Professional film, especially when bought in bulk, doesnt really cost that much more per roll than cheap drugstore film. And it costs just as much to develop a roll of crummy film as it does good film. So why not spend the small percentage extra and go for good film?
Why do photo shops store some film in refrigerators?
All film exhibits slight colour shifting as it ages. It also gets grainier as it gets old. These changes are not acceptable for professional photographers, particularly those in commercial photography who require absolutely dependable colour stability.
Professional film is thus stored at cool temperatures in order to slow the ageing process. By contrast, consumer film is shipped out pre-aged and generally sits around in shops for who knows how long, and so its colour rendition is considerably less reliable.
Is it true that film contains animal gelatine?
Yes. It appears that all film manufactured commercially today contains silver halide crystals suspended in a gelatine emulsion, which is animal-derived protein - boiled animal bones and hides. I believe all major film manufacturers use animal gelatine, but please email me if you know of any which dont. This is obviously a problem for people who, for ethical, religious or philosophical reasons, want to avoid animal-based products.
If you find this a matter of concern you might want to consider digital photography. Digital cameras and printers have obvious environmental issues surrounding their production and eventual disposal, but animal gelatine is not, to the best of my knowledge, used.
What is chromogenic black and white film and why can it be developed in colour photo labs?
Traditional black and white film was usually silver-based for most of the 20th century. To be more accurate, silver halides were and are used to record and show images. Other metals were used as well, but silver became dominant.
Colour film uses silver to record the image as well, but the silver is typically washed out of the film during processing and colour dyes used to store the final colour image. Standard colour print film, known as C-41, uses a complex chemical process with chromogenic dyes. (the word chromogenic comes from the way the colour dyes are generated in the film during processing) And of course someone realized one day that instead of using these chromogenic dyes to record colour information you could use a simplified chromogenic process to record black and white information.
So thats what chromogenic film is - black and white film which uses chromogenic black dye rather than silver. The advantage is that you can take chromogenic film to any minilab or wherever and have them process your black and white photos using standard colour chemistry. Minilabs cannot process traditional silver halide black and white film using their automated colour processing machines because of the incompatible chemical processes.
Printing and processing.
I got an enlargement made and tons of stuff is missing off the edges!
There are two possible issues here. First, labs tend to crop off a small amount on all sides when making enlargements. Thats how the printing machines work. The amount trimmed off is fairly minimal, however.
Second, you may be having an issue with differing aspect ratios. The ratio of the tall to wide dimensions in regular 35mm film is exactly 2:3. Unfortunately a lot of popular print and picture frame sizes do not have this aspect ratio for random historical reasons. If your photo is missing stuff from the sides but not the top and bottom then you probably have an aspect ratio issue.
For example, in North America 8"x10" is a popular picture frame size. And 8"x10" obviously doesnt have an aspect ratio of 2:3. If you want an enlargement containing all the stuff thats on the negative youll have to choose an enlargement size that can accommodate this. In the example above 8"x12" is probably your best bet. Alternatively you could ask for the image not to be cropped, but a non-cropped 8x10" photo will have white strips along the top and bottom edges to make it fit, much like a movie on TV is letterboxed.
My pictures all look lousy! Why?
This is such a general question that its hard to know where to start. There are so many possible reasons why a photo could look bad. Maybe theres a problem with the cameras focus or metering. Maybe its a poor lens. Maybe the lens or camera are out of alignment. Maybe your technique is bad - too much camera shake, perhaps. Maybe your composition is bad. Maybe you focussed on the wrong thing. Maybe you need to learn about lighting and using it effectively. Maybe you used onboard flash, which tends to make things look flat. Maybe you took the film to a lousy lab. And on and on.
The first thing I would do if your photos look sort of bad is to see if its the lab. The lab is the final link in the chain that determines the quality of your photos, especially if youre making prints. A lab with badly maintained printing machines operated by poorly-trained monkeys, like the typical drugstore, will produce really crappy prints.
The standard recommendation, therefore, is to try shooting a roll of slide film. When you look at the slide youre looking at the first generation image up there on the wall. Theres no lab between you and your film messing things up. If your slides look poor then its time to look into other possibilities.
My pictures look grainy. Why?
If you have noticeable grain or speckles on your film-derived prints its very probable that your negatives are highly underexposed (ie: they were not exposed to sufficient light). When photo printing machines encounter underexposed negatives they tend to boost the brightness to compensate, which tends to reveal bad speckly grain. Take a look at your negatives by holding them up to the light. If they seem very transparent and light then theyre underexposed. There isnt much you can do about the existing negatives but it suggests that perhaps you need to meter more carefully - or apply some exposure compensation - in the future.
If you shot digitally then you may have used a high ISO setting. This is particularly the case with older EOS digital cameras. ISO 100 is pretty well noiseless, but the higher you go with your ISO settings for low-light photography the more random rough-textured "noise" appears on the image.
There are other possibilities. Its possible that you had the ISO film setting on the camera wrong, for example. Its also possible that the lab messed up the development of the film.
What is colour temperature?
The definition of colour temperature is highly technical - it refers to the colour of light produced by a theoretical black body object thats heated to a certain temperature, measured in Kelvin temperature units.
Though based on physical theory theres nothing abstract about this. The concept is crucial for colour photography. Essentially it boils down to the fact that white is not an absolute concept.
White light produced by a light source with a low colour temperature such as a tungsten light bulb is very orange compared to the bluish white light produced by a light source with a high colour temperature , such as the sun. This isnt really apparent to the human eye under normal circumstances because our brains adjust automatically to changing colour conditions. Its only usually noticeable when light sources with different colour temperatures are seen together. For example, the incandescent light spilling out of the window of a house looks remarkably yellow or orange at dusk, when everything outside is lit with the very blue light from the darkening sky.
Unfortunately, film is not so flexible. Film emulsion must be designed from the start to assume a certain colour temperature as its white point. Most films are daylight-balanced, which means they assume that the light from the noonday sun (in a temperate place) is white - roughly 5500K. So if you take a photo indoors under tungsten lighting using daylight film youll find everything looks very orange or yellow. You can also buy film thats balanced to tungsten light - typically 3200K. If you take a photo outdoors using such film youll end up with a picture with a very blue cast.
Digital cameras generally do not have a problem with colour temperature in the same way. Since digital data can easily be reconfigured its a simple task to alter the white point of a digital camera - a process called white balance. Most digital cameras and all EOS digital cameras have preset white balance settings for common light sources - daylight, tungsten light bulbs, shade, etc. EOS digital cameras also let you set your own custom white balance. However, if you forget to set the white balance correctly when taking a photo you might end up with similar problems to film colour casts, assuming your camera wasnt using automatic white balance.
My pictures have strange colour tints. Why?
The most obvious possibility is, of course, a problem at the lab. This shouldnt be a problem with labs that demonstrate a modicum of care, but strange things happen. Once I took a test roll of film into a local corner one hour photo lab and got back a stack of pictures of my green fiancée. Green. Really. It was like I Married a Martian. I took the same negatives to another lab and came back with a stack of nicely coloured pictures - Martian princess no more.
The most likely possibility after that is colour temperature issues. Here are some common scenarios, expanding on the colour temperature section above:
Photos, particularly indoor photos, have a yellow-orange tinge to them.
You probably used daylight-balanced film under tungsten (incandescent) lighting. Tungsten light records as yellow-orange on daylight film.
To avoid this problem either use tungsten-balanced film, use flash, turn off tungsten lights and rely on daylight coming in through windows, or put cooling (blue-tinted) filters on your lens.
Foreground stuff looks fine but background stuff is tinged yellow-orange.
You probably used flash under tungsten lights with daylight-balanced film. The light from flash units is designed to be the same approximate colour temperature as sunlight. So all foreground objects illuminated by flash will appear normally coloured on daylight film.
Theres no real way to avoid this problem if youre shooting with flash. You could either not use flash or turn off any tungsten lighting. Or you could use tungsten-balanced film and put a warming filter on the flash head.
Photos, particularly outdoor photos, have a blue tinge to them.
Less common, but you may have used tungsten-balanced film under sunlit conditions. Regular daylight records as blue to tungsten-balanced film. Switch to daylight film or put a warming (yellow) filter on your lens.
Indoor photos look greenish.
Most likely the pictures were taken under fluorescent lights. Theres no such thing as fluorescent-balanced film, but you can buy magenta-tinted filters (FL filters typically) which can help colour-correct fluorescent light. Note that many modern fluorescent bulbs dont have this same problem.
Which is better? Matte or glossy?
Neither. The choice of matte or glossy print surfaces is a matter of personal preference.
Some people prefer matte because its less reflective - so theres less glare - and because fingerprints tend to show up better on glossy surfaces. Other people prefer glossy since the lack of texture can make the image look a bit sharper. Many others prefer pearl or semi-matte surfaces as a compromise between the two.
What is cross processing?
Cross processing refers to developing a film using a development process that was not intended for it. It usually means developing slide film using a print developing process or vice-versa.
Cross processing is sometimes done because it yields interesting, albeit unpredictable effects. Contrast tends to be enhanced and colours tend to shift. Edgier fashion and commercial photography is sometimes done using cross processing. Note that many labs wont do cross processing, sometimes because their automated machines refuse to let them do it, sometimes because theyre concerned about their photochemicals getting contaminated and sometimes because they have no idea what it is.
What does archival mean?
The ravages of time are cruel, though more cruel to some materials than others. Archival media is paper, film, etc, which is supposed to hold up reasonably well to the passage of time. How well it does is dependent on a host of factors, and theres no universal definition as to what is truly archival quality material and what is not.
Paper is probably the main area of concern when it comes to archival materials. Standard commercial papermaking processes result in paper with a high percentage of acidic materials. And unfortunately this acid causes paper yellowing and deterioration (crumbling) - sometimes in months, often in years and always in decades. For that reason archival papers must be acid-free, or have a neutral or slightly basic pH. Papers are also often buffered, which involves the addition of an alkaline material such as calcium carbonate to help ensure long-term pH neutrality.
Another problem with papers made from wood pulp (as opposed to higher quality papers made from cotton) is the presence of lignin. Lignin is a naturally occurring part of a plant cell, but is an undesirable substance in paper as it can contribute to the long-term deterioration of the material. Higher-quality paper has had most of the wood fibres lignin removed during manufacture.
Photo binders must also be designed with archival properties in mind to avoid damaging photographs. Many photo binders use thin plastic sheets to keep photos in position. Mylar sheets appear to be pretty stable, but cheap products may use lesser quality plastics which actually stick to the photos, ruining them. The pages of the binders must also be made of acid-free paper if they come in contact with the photographs, or else youre defeating the purpose of using acid-free paper in the first place.
Colour dyes in film.
Dyes are another area of concern when it comes to archiving photographs. Traditional silver-based black and white processes are generally remarkably stable - a black and white picture taken a century ago can look just as good today. Colour dyes, however, are notoriously difficult to keep stable. Colour dyes used in motion picture film in the 60s and 70s, for example, are fading at an alarming rate.
The same problem applies to the colour dyes used in many forms of colour still film. Some colour film technologies, notably Kodachrome, have proved to be very stable in dark storage, but typical cheap colour print film (chromogenic film) doesnt have particularly good archival properties. It might be worth doing high-resolution scans of important photographs now, before the colour has deteriorated at all. You then have the problem of preserving the digital data (see below) but at least the colour in the digital scans wont fade.
Dyes used by inkjet computer printers have similar problems with colour fading. Some early inkjets, in fact, were notorious for severe colour fading and colour shifting problems, particularly when exposed to ultraviolet light. Many inkjet makers indicate that their products are colourfast or archival, but these claims dont follow any particular standards.
Computer data itself is a complex problem as well. Binary data itself can be duplicated over and over completely error-free, but the media upon which the data is stored is subject to failure over time. Floppy diskettes, for example, suffer from whats jokingly called bitrot - they lose their magnetically-encoded information over time. Hard drives pack a huge amount of data into a tiny area on disc, and its unclear how long they can retain their data.
Recordable CDs (CD-Rs) are a technology heavily relied upon for archiving digital data. Accelerated tests performed on the cyanine (typically green or blue-green), metal-stabilized cyanine (also typically green or blue-green), phthalocyanine (typically gold or greenish gold) and metallized azo (typically dark blue) dyes used in different types of CD-Rs suggest that CD-Rs will enjoy many decades - perhaps even a centurys worth - of reliability, but only time will tell how stable they really are.
Not only are the dyes a factor but the stability of the polycarbonate plastics, the environmental storage conditions (eg: abrasion, water vapour, airborne pollutants such as sulphur, and shock can all degrade CDs), the chemicals used in any adhesive labels or felt-tip markers, and the burn power of the CD burner itself are all elements which will determine how long the discs remain readable. Not only that but 550 MB/63 minute CDs, which use a slightly wider track spacing than 650 MB/74 minute CDs, are often more reliable in many older burners and readers.
And of course who knows whether the actual equipment to retrieve data from a given medium will be around in decades or centuries hence. How many people today have the gear required to retrieve data from a computer cassette recorded in 1977, for example? Or a Bernoulli cartridge from the 80s? Will it be easy to copy that precious digital photograph from a CD in 2050? Will anybody be able to retrieve data from a corrupted flash memory card in a centurys time? From this point of a view a photographic negative may well have longer longevity.
What to do?
Well, its basically impossible not to have some colour or data loss over the years, but there are a few things you can do to help minimize the problem.
About online discussions and this FAQ.
How is PhotoNotes.org funded?
This site and its extensive content are funded entirely out of my own pocket and reader donations. The server hosting these pages is in Islington, London, England.
At this time it isnt supported in any way by advertising or corporate sponsors. So if you found any material here useful or interesting please consider making a donation to keep it on the air. Thanks!
You may also find my book, Mastering Canon EOS Flash Photography, to be of some interest if you want to learn more about flash.
What are some common photography-related spelling errors?
Heres a short list.
Incorrect Correct Amature Amateur Aperature, apature, etc Aperture Cannon Canon (the camera company) Copywrite, copyrite, etc Copyright Flourescent Fluorescent Infared, infered, inferred, etc Infrared Lense* Lens Marco Macro Manuel Manual SRL SLR (ie: single lens reflex) Wide angel Wide angle
* Oddly, Merriam-Webster claim that lense is an acceptable alternative spelling for lens. However, I have never seen lense in print and the Oxford English Dictionary lists only lens, so Im presuming it was a temporary lapse of judgement on their part, like claiming that cigaret is correct spelling.
Why are people on discussion groups such mean snobs?
Thats a good question and theres no one answer to this. First off, yes, some people on discussion groups can seem like mean snobs. They may be generally cantankerous, they may be disgruntled wannabe photographers bitter about anyone else having fun, they may be insecure jerks and so on. They may also be experienced photographers who have simply forgot the type of perfectly reasonable questions that novices may ask.
But its also possible that they may be responding to something else. If you get a strongly negative reaction to your online post, consider some of the following points:
Did you post in uppercase or use a lot of punctuation?
In the online world, UPPERCASE LETTERS ARE INTERPRETED AS YELLING. So if you posted a question like, HELP ME MY CAMERA IS BROKEN!!!!!!!!!!!!!!!!!! you might annoy a lot of people. Rather than posting big solid blocks of text, try to break up longer pieces into easier-to-read paragraphs. This may sound trivial, but online your words are who you are. Posting in uppercase is like lurching up to someone in real life and bellowing or belching in their ear. First impressions matter.
Did you have a concise and specific question?
Photography is a precise field in many ways. Dont expect a helpful response if you post a question like, my flash wont work! Be as specific as you can. A question like, I have a Canon EOS A2. It takes photos fine, but its built-in flash no longer pops up is much more likely to garner responses. Similarly, a vague question with no context - eg: is the Canon 28mm lens any good? - is very difficult to answer. Good for what? What do you want to do with this lens? And which lens? Canon make two 28mm lenses for the EF mount. Or a completely open-ended and general question like, Canon EOS Rebel - any comments? How is anybody supposed to know what you mean by that? Another really annoying thing is to formulate a subject line as a statement when its actually a question. Compare the difference between Company X going bankrupt and Is company X going bankrupt?
Also, try not to post rambling novels. Short, succinct and specific questions are usually the best, assuming you actually want an answer.
Did you ask a question thats been asked zillions of times before?
Now, to be perfectly fair, as a novice you may not know that the question has been asked before. So have a look. Its really irritating for regulars to a discussion group to have newcomers barging in every day and asking the same question over and over. Its only polite to do a quick search of the archives (nearly all discussion groups have some form of archive system, and Google has a pretty complete Usenet archive) to see if your question has been asked before. Chances are it has. Not only will you not annoy regulars but youll probably learn a lot of useful information too.
Did you come across as demanding?
Sometimes people post belligerent posts with a pushy tone as though they were entitled to an answer from an underling. Remember that online discussion groups are full of ordinary folks who like chatting with other photographers about their hobby, vocation or passion. Theyre not paid flunkies or whatever - they want to help other folks for the sheer fun of it. So be polite and friendly and people will be polite and friendly right back.
The other day I came across a post from a guy who started out, I know this has been answered here before, but I dont have the time to look it up.... Well. Why should I waste my valuable time helping him if he cant even take a moment to scan the archives? Hes obviously decided that my time is less important than his.
Did you follow the posting guidelines?
If you have a question about Canon lenses then you shouldnt post your question to the medium format photography forum. If the forums posting policy specifically bans advertising then you should respect the rule and not post ads. Posting the same identical question to multiple forums on the same site tends to make a lot of people irritated - especially if your previous question has already been answered before. And so on.
And if youve gone over this list and you still got a rude response to your post then, yes, you probably just ran into a cantankerous oldtimer who had a bad morning. Ignore him or her and move on.
Why is this FAQ full of spelling and grammar errors?
It isnt. Well. It probably has some, but I dont think its full of them.
It does, however, generally use Canadian spelling and grammar, which may be confusing to those more familiar with US or UK conventions, since Canadian writing tends to be a random hybrid of both. (eg: Z endings for words like analyze, but U for words like colour)
Why are there no photographs or illustrations in this FAQ?
One word: bandwidth.
While this Web site is free for everyone to read, it definitely costs money to run. And so I didnt want to load down the pages with photos and graphics that cost even more network throughput to transfer, valuable as such illustrations can be.
If you found any of this material useful interesting and youd like to make a donation to help defray the costs of running this site, please click on the donation icon.
I have a question that isnt covered by this FAQ. Can I email you?
Actually, itd probably be better if you were to post your question to an online photography forum like Photo.nets EOS forum or my PhotoNotes discussion forum.
I prefer this for two reasons. First, I get a fair bit of email. And while answering email and answering questions on online forums take the same length of time, the latter benefits far more people. And second, I make mistakes. If I reply to an online forum and Im wrong someone will probably correct me. And thats to your benefit too. Im no final authority on this sort of stuff.
VII - Links.
Here are some useful sites for leaning more about EOS cameras and photography in general.
Canon USAs Web site, listing all current EOS products:
Canon Japans official site with pretty well every Canon camera and lens made:
An American site packed with useful articles and discussion areas:
A German site with photography articles and equipment comparisons:
PhotoZones section on Canon EF lenses:
A Swedish site with comprehensive lens comparisons:
- NK Guy, PhotoNotes.org.
Disclaimer and copyright:
This document is copyright © 2002-2013 NK Guy, PhotoNotes.org. This information is provided with neither warranties nor claims of accuracy or completeness of any sort. Use this information at your own risk. All trademarks mentioned herein belong to their respective owners.
I wrote this document in the hope that others in the Internet community might find it useful or interesting. However, I dont think its reasonable for anyone else to earn money from - or take credit for - my work.
Therefore you may copy and print this document for your own personal use. You may not, however, reprint or republish this work, in whole or in part, without prior permission from me, the author. Such republication includes inclusion of this work in other Web sites, Web pages, FTP archives, books, magazines or other periodicals, CD-ROM and DVD-ROM compilations or any other form of publication or distribution. Please do not frame this site within another.
Please send feedback if you find this article to be of interest or value or if you have any comments, corrections or suggestions.
Please also consider making a donation to help defray some of the costs of building and maintaining this site. Thanks!