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Notes on the Canon Speedlite 270EX Flash Unit. DonationsCopyright © 2009 NK Guy

I’m currently working on a new book on Canon EOS flash photography (to be published later this year by Rocky Nook) and, thanks to the kind assistance of Canon Europe, I’ve been able to test an early production unit of the new Canon Speedlite 270EX flash unit. For more details on EOS flash in general please consult my flash article.

The Canon Speedlite 270EX is a new portable hotshoe flash unit, introduced in early 2009 with the EOS 500D/Rebel T1i/Kiss X3 digital EOS SLR camera. It replaces the 220EX in the product lineup. The 270EX is a tiny unit made of smooth black plastic, and is powered by two AA batteries. (not 4, like almost all other Speedlites) Like recent 430EX II units, it’s made in China. (previously all Canon flash units were made in Japan or Korea) It feels fairly sturdy, and the hinge mechanism for the tilting head seems very solid and reassuring. It has a new-style metal foot, with a slide-locking mechanism (not the rotating lever lock found on more expensive Speedlites)

Flash head movements

Unlike the 220EX, the 270EX has a tilting head, though it still lacks swivel. You can bounce upwards to the ceiling at 90°, with additional detents at 60° and 75° as well. The head pulls out to allow for the tilt. When it does so its coverage shifts from that of a 28mm lens (on a 35mm/full frame camera) to 50mm. There’s a tiny microswitch visible inside the unit which lets the camera know which position the head is in. Based on the behaviour of other Speedlite products, I would theorize that this switch tells the camera whether flash is direct or bounce, thus enabling or disabling E-TTL II lens distance data, though this is purely a guess on my part.

The camera knows the flash zoom position too since it’s actually displayed on the Speedlite control menu screen - at least on those camera bodies which can control recent Speedlites in this way. Effectively the 270EX represents a transition from physical switches on Speedlites to digital camera-based control. In fact, there’s only one switch on the 270EX - an on/off slider. There’s a flash-ready red LED, but unlike most previous Speedlites this LED does not double as a manual flash-firing pushbutton.

Digital control in this fashion is a great way for Canon to unlock all kinds of useful features in their flash units at low additional cost, since physical buttons and switches aren’t needed. It does have two drawbacks, though. First, clicking through camera menus is more time-consuming than flipping a simple switch. Second, support for these extra features is limited to EOS digital cameras from the EOS 40D onwards.

Automatic menu control

So, if you have a recent digital EOS body capable of controlling external Speedlites, you have a reasonable amount of control over the 270EX’s capabilities. The EOS 450D, EOS 1000D, EOS 40D, EOS 50D, EOS 1D Mk III, EOS 1Ds Mk III, EOS 500D and EOS 5D Mk II all have this ability. Of these bodies only the last two can enable the unit’s AF assist (more on that later) without a firmware update.

The camera’s menu system lets you enable the following functions on the 270EX:

- Flash firing: on or off
- Metering: E-TTL or E-TTL II (depending on the body) or manual.
- Manual output control can be set over a 7 stop range from full power to 1/64.
- Shutter sync: first or second curtain (default first curtain)
- FP mode/high speed sync: on or off (default off)
- Flash exposure compensation: Camera-dependent
- E-TTL: Evaluative or averaging metering; camera-dependent, default evaluative
- AF assist: on or off
- Quickflash with continuous shooting: on or off (default off)
- Save Energy/auto power off: on or off (default on)

If you’re using an older camera which lacks menu control over external Speedlites (any film camera or a digital camera which predates the EOS 40D) you may be able to set some of these settings, such as curtain sync or flash firing on or off. But certain features, such as manual flash, disabling SE mode or enabling autofocus assist, will not be available to you.

Autofocus assist

This is the biggie. Most Speedlites contain bright red LEDs which project a pattern of lines. These lines are used by the camera’s autofocus system to lock on focus when light levels are low. The 270EX is one of the few Speedlites to lack this feature.

Instead the 270EX can pulse its flash tube at a high rate to produce enough light for the autofocus system to work. This is the same technique used by recent consumer to midrange Canon EOS cameras.

The reasons for the lack of a red light on the 270EX are keeping costs down and keeping size down. Most smaller Speedlites with red AF lights have limited single AF point coverage. Flash units which can cover the autofocus points of cameras with multiple points generally have large lenses and plastic cover plates. An AF assist light which covers the central point only can be confusing to users, so a light which covers all points is obviously preferable. The 270EX obviously covers the full range of points on all current EOS cameras with ease, since it's using the scene-illuminating tube.

The drawback to using the main tube for AF assist is obvious: the high frequency blast of light from the flash unit is distracting and irritating to subjects. So this type of AF assist is not popular with experienced photographers.

Note also the restriction regarding automatic menu control. You cannot enable AF assist on this unit if you’re using a camera which lacks external Speedlite control. Of those cameras, only the 500D/Rebel T1i and 5D Mark II can enable the AF assist without a firmware update to the camera.


Another thing of note is that this is the first Canon Speedlite to drop legacy TTL support. The flash unit cannot work with older film-based cameras which lack E-TTL. Up until now all EX flash units have been fully compatible with all EOS cameras made since 1986. The 270EX requires a type A film camera that’s got E-TTL support, or any post D30 digital EOS camera.


Like all tiny flash units, the 270EX can’t produce a lot of light. It has the same guide number as its predecessors (22, metric) except when its head is zoomed to the 50mm ("tele") position, at which point its GN is 27. This is an important point, given its bounce and FP flash capabilities. Still, given the increasingly good low noise capabilities of most modern digital SLRs at higher ISO settings, this shouldn’t be a huge limitation. Just don’t expect to illuminate a grand ballroom with this one.

Other features

Surprisingly the 270EX supports certain other features, including the ability to transmit colour temperature data to compatible bodies, and support for modelling flash when the depth of field button is pressed. As noted above, it supports first and second curtain sync, and FP mode flash can also be enabled, but only with later EOS digital cameras. Unsurprisingly, though sadly, it lacks wireless E-TTL slave support. A shame, as a tiny E-TTL slave would be a great tool for creative lighting, much like Nikon’s SB-R200 units.


There are really two markets for tiny flash units. One is primary and huge: amateurs and beginners who just want a simple affordable flash unit that’s a bit more powerful and flexible than the built-in flash. The other is secondary: advanced amateurs and professionals who occasionally want a little touch of portable fill-flash or who want AF assist at low light levels. This secondary market is much smaller, but much noisier on the Internet. Unfortunately two specific limitations - the absence of red AF assist and the limited control for owners of older EOS bodies - mean that the 270EX is not particularly well suited to the needs of the second group.

In short, the 270EX is a relatively affordable, lightweight flash unit for beginning users who own recent model digital EOS cameras. It isn’t great for teaching the basics of off-camera flash, but is ideal for portable on-camera use.


- NK Guy,

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