Lightest Speedlight

[alexkrich]

Greetings,

I am looking for the smallest, lightest Speedlight which could be remotely controlled by my 7D.

Any suggestins will be gratly appreciated. 

Thanks!

[diverhank]

That would either be the 90EX or the 270EXII.  The 90EX is actually a Master capable flash designed for the EOS-M but the 7D already has that capability.  I'd recommend the 270EXII as it has a lot more power than the 90EX.

[TCampbell · Accepted solution]

I think probably on the 430EX II will qualify for what you want.

Keep in mind that Canon's model numbers are based on the "guide number" of the flash.  E.g. a 270EX has a "guide number" of 27 meters.  A 430EX II has a "guide number" of 43 meters, etc.  

The guide number indicates the distance at which the flash can properly illuminate a subject if the camera is set at ISO 100 and using a lens with an f/1.0 aperture.  

Nobody has a lens with an f/1.0 aperture (Canon used to make one years ago) but the baseline is used because it makes the math easy.  You divide the guide number by the f-stop you actually plan to use when shooting... and that's your distance.

So, for example, a 430EX II (guide number of 43 meters or 141 feet) at f/1 but if your lens is at, say, f/5.6 it's only about 25 feet.

The 90EX can be used as a "master" to control slave flashes, but not as a slave flash.  The 7D already has a built-in master so you wouldn't need yet another master flash.  Also... the 90EX has a guide number of 9 meters... or about 29 feet at f/1.0.  But at f/5.6 it's ONLY 5.2 FEET!  To increase that distance, you have to increase the ISO sensitivity of the camera.  At ISO 400 it's good for about 10 feet.

The 270EX II (but not the original 270EX) does support "slave" mode but does NOT support "master" mode.  It has a guide number of 27 meters or 88 feet at ISO 100 and f/1.  At, say, f/5.6 it's about 16'.  Also keep in mind that if you add light modifiers to soften the look of your flash, most diffusers tend to eat about 1 stop worth of light (50%).

A 430EX II does support wireless slave mode and will work with a 7D for off-camera flash as long as the 430EX II can "see" the 7D's flash.  It's uses an optical system to communicate (the flash on the 7D pulses rapidly to send instructions.)  The 430EX II supports "slave" mode but does not support "master" mode.  The 580EX II supported both master and slave modes and the new 600EX-RT supports everything and can communicate via radio (line-of-sight not necessary.)

I wouldn't recommend a flash weaker than the 430EX II because you're getting to a point where the flashes aren't very powerful and you have to rely on low-focal ratio glass and/or cranking the ISO on the camera to compensate -- especially if you start modifying the light to soften it... either by bouncing the flash or by using any type of light-softening modifier.