Canon & Nikon TTL flash compared

Nov 16, 2008 | Flash | 12 comments

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.

Taken in Bristol using a Canon 5D, 16-35mm lens, STE2 and 580 EX2 Speedlite.

Taken in Bristol using a Canon 5D, 16-35mm lens, STE2 and 580 EX2 Speedlite. Extreme use of exposure reduction in the background of shots like this (typically minus 3 stops) requires manual mode on the 5D.

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.

Taken in Melbourne using a Nikon D3, 24 -70mm lens, SU800 and SB800 Speedlight.

Taken in Melbourne using a Nikon D3, 24 -70mm lens, SU800 and SB800 Speedlight. The Nikon range of professional SLRs allow plus or minus 5 stops of exposure compensation without resorting to M or manual mode.

Fuzzy logic

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.

Taken in London using a Canon 5D, 24 - 70mm lens and a 580 EX mk2 Flash used on camera.

Taken in London using a Canon 5D, 24 - 70mm lens and a 580 EX mk2 Flash used on camera. When I use flash in this way I often need to increase it's output because the flash cuts out early if it sees itself come back in specular reflections.

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.

Taken in Melbourne using a Nikon D3, 24 - 70mm lens, SU800 and SB800 Speedlight. I'm not a great fan of tilted pictures but somehow I got away with this. Minus 2 stops of ambient exposure and plus 2 stops of flash to compensate.

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.


  1. John Harris

    Hi Damien, fantastic blog resource – so much so that I decided to go back and re-read all of them! In doing so, a question occured to me.

    I am a Nikon user and normally shoot in AP mode but have decided to try using manual control for flash shots. I understand the fact that in AP mode, a negative exposure compensation adjustment on the ambient exposure needs to be ‘offset’ by a corresponding positive exposure compensation value on the flash to get a correct flash exposure.

    However, would I be right in saying that when using manual mode this is not necessary as the camera doesn’t ‘know’ that you are purposely underexposing and therefore still calcualtes the correct flash output duration (or is the camera so smart that it detects the fact that the manual setting is below that for a normal ambient exposure and therefore drops the flash power accordingly???).

    Hope that makes sense.


  2. Rob Slaski

    Hi Damien,

    Perhaps you should post a review of the G10 – would certainly drive extra traffic to your site. I know I’d be keen to hear your views on it.

    Do you never sleep?


  3. damien

    Hi Rob,

    My G10 arrived yesterday but Calumet sent me a CF card with it and not the SD card that was supposed to have been bundled with it. So I’m a bit fed up with them as I can’t yet use the camera. They claim they will send me an SD card in a few days time.

    Damien :-(

  4. Rob Slaski

    Thanks Damien, not sure what I did wrong the first time around but you’re right it does work!

    Seems this set up could work well in my studio using the STE2 to trigger a 580 as a flexible hairlight, while the Bowens key & BG lights stay at a fixed setting…. will need to experiment!

    Thanks for the inspiration. By the way have you been tempted to get a Canon G10 yet?!!


  5. damien

    Hi Rob,

    It’s Damien here, You plug the PW’s into the pc socket outlet on the side of the camera and have the STE2 on the top. I’ve got a bit of Velcro on my STE2 to take a corresponding bit of the opposite sex on the Pocket Wizzards. (I’m not sure Velcro is sexed but you know what I mean.


  6. Rob Slaski

    Hi Martin,
    Can you explain a little further how to combine STE2 driven TTL off camera flash at the same time as triggering a second off camera (non TTL) unit with the PW’s?

    I can’t get this configuration to work on anything other than manual (the ETTL preflash sets off the PW flash)

    Great blog by the way.

  7. Lius

    Hi, I’m from Indonesia.
    One of canon wireless lighting system drawbacks is, you can’t use the rear/second curtain sync. You can only use it on camera or using the off shoe cord (CMIIW).
    Very nice and inspiring blog :)

  8. martin

    As Damien is tied up teaching, I’ll answer that and he can correct me if I am wrong.

    The broncolor would be triggered by a pocketwizard pair. The speedlight would have been triggered by an ST_E2 which means the PW transmitter would have been plugged in to the sync socket of the camera.

    The alternative would have been to trigger the speedlight with a PW too but then you would be controlling the speedlight output manually.

  9. Kevin Moore

    Makes a world of diffrence to read something without a bias.Great insight saved me a purchase on EX580 Mk2 as I have been more than happy with my Mk1. Damien on your main website you have an iamge when you used a speed light and your Broncolor. What did you use to trigger them ?

  10. UKpro

    I switched from Nikon to Canon back when the 10D and 1D were top of the Canon line. At the time Nikon users had been forced through three flash upgrades to get to a system that worked with digital. I’m still using my Canon 550EX that dates from film days. Now it seems on balance that the Nikon flash line is one step ahead of Canon. The SB900 does seem to move the bar. And not forgetting for Macro shooters the Nikon wireless system is much better than anything Canon can offer. Competition is good, we all win in the end :)



  1. Nikon D90 Camera - Nikon D90 Camera... One of my favorite photography quotes by Ansel Adams: There are always two people in every picture:…

Ask a question or leave a comment. All comments get a reply.