Canon 5DMKII Manual Flash Works in Live View Silent Mode 1!

[ghwanner]

I ran some tests recently using a 270EX flash mounted on my Canon 5DMkII with the latest firmware (2.0.7). In the Canon manual as well as in the excellent book Mastering Canon EOS Flash Photography, it is stated that with the camera in Live View Silent Mode 1, use of a Canon dedicated flash will result in disabling the silent mode (equivalent to the Silent Mode Menu Disable function). I found this to be true if the Flash Mode Menu is set to E-TTL.

HOWEVER, if the flash mode is set to Manual, the flash will fire at the selected flash menu power level WITHOUT disabling Silent Mode 1 (e.g. the mirror will not drop down and the first curtain remains open for the exposure). This is important if you are taking close-ups with a macro lens (or a telephoto zoom + 500D closeup lens) at high magnifications as it avoids potential vibration due to mirror action and first curtain opening. It is also very useful if you are using the camera and dedicated flash for photomicrography. Use of a Canon dedicated flash in manual mode with live view silent mode 1 is not discussed anywhere that I have been able to find.

Obviously, you don't get automatic flash exposure computation, but you can easily adjust the flash to the requisite power level for a correct exposure by taking a few test shots and chimping the result.

Note that this will NOT work with a non-dedicated flash connected to the PC terminal - the flash won't fire unless you disable silent mode.

[nkg]

That's a good point. When using E-TTL metering it's necessary to move the mirror up - you can't both meter and send light to the sensor. However, manual mode on a Speedlite doesn't require metering.