There is one big operational difference between the Canon and Nikon TTL flash systems with regard to exposure compensation logic. Both set ups are equally valid but I thought the difference worth sharing with you. I have also noted down a few minor differences for good measure.
Over the past year I have been in the fortunate position of using both the Canon and Nikon TTL flash systems in the real world. Outside in sun, rain, sleet and overcast conditions plus inside in just about every lighting situation imaginable. My 11 month old Canon 5D has over 40,000 frames on the clock and my month touring Australia in 08 saw me put 10,000 frames on a Nikon D3. In this period I have been teaching the use of off camera flash to seminar delegates and I must have established the flash handling characteristics of just about every camera and flash unit combination in both the Nikon and Canon line ups.
Exposure Compensation & TTL
Nikon: If you set up your Nikon camera in either A or P mode and dial in -2 stops of exposure compensation to darken the background of an image you need to dial in +2 stops of flash compensation in order to correctly expose the foreground. This logic uses the assumption that if you select compensation you want it to effect all aspects of the exposure.
Canon: If you set up your Canon camera in either Av or P mode and dial in -2 stops of exposure compensation to darken the background of an image you can leave the flash compensation alone in order to correctly expose the foreground. This logic uses the assumption that if you select compensation you want it to only effect the ambient exposure.
Both systems are equally valid but might just catch you out if you are contemplating a switch one way or another between Nikon and Canon.
Menus, sub menus, and sub sub menus, are the order of the day now with electronics. Canon succomed to this when they replaced the very well appointed 580 EX flash gun with the Mk 2 version. Instead of a single flick of a switch to get from on-camera TTL to wireless TTL using an STE2 commander, the Canon 580 EX2 needs an intricate sequence of button pushes, holds and knob twiddling. The switch may be a bit more expensive than a few lines of computer code but it gets the job done at the speed you want it. The Nikon SB800 is no less annoying with it’s menu system. You get there in the end with both systems but not before your subject has moved on or you’ve missed the shot.
The Nikon SU800 commander system lets you take independent TTL or manual control of more flash units than the Canon STE2 system but I’ve yet to see a photograph taken using this multi power set up that is inspiring. Yes, two power levels on three flash heads could be spot on and I’ve used such a set up on various occasions. Both the Canon and Nikon set ups will allow you to do this. In short the Canon and Nikon systems are both capable, however I find the Nikon options overly complicated whilst the Canon one is perhaps a bit simplistic. With the Canon STE2 the flash power is divided in ratios so as long as you are happy to think in term of 1:3 etc you’ll be fine. The Nikon SU800 and the STE2 have equal infrared trigger capability and repeat exposure accuracy.
The SB900 is now out and offers a greater manual zoom range than it’s predecessor. No doubt Canon will follow suit and deliver a replacement flash unit too. Don’t feel you have to wait for the new kit though as the existing Speedlites are more than capable of achieving masterful results in the right hands.
TTL remote commanders
The Canon ST-E2 is £129 from Amazon in the UK and the Nikon SU800 commander is a whopping £225 again from Amazon in the UK. Both units use odd battery types not readily available at convenience stores and (IMO) really ought to use penlights like the flash guns they trigger. The Nikon unit is bigger and a bit heavier. It relies on menu systems again and utilises a LCD display to facilitate this. The Canon unit uses switches – horray! I and many other users of the Canon ST-E2 have found the little red plastic lens on the front of the unit falls off from time to time. I used super glue to fix mine and the fault has gone away.
Have your say
Have you swapped sides from Canon to Nikon or visa versa? What have been your experiences with regard to using TTL off camera flash? Email me here with your findings and a few of your pictures. The best of these will be published online for other photographers to enjoy. All contributions will be fully credited together with links to the authors website or blog.