After many readings about issues with 5D mark II and flash, I was a little uncertain when I decide to buy 5D mark II. But I knew that many of users have "problems" with all EOS flashes, not just with 5D mark II. I talked with two who knows how things works and they use this 5D mark II and they didn't have any problems.
I made some test shots and I can say that it works like on 30D. Good (I can't say excellent), but it can be better.
In my test shots I didn't avoid vignetting, I didn't use diffuser, I didn't look at composition and I use direct flash. Flash was powered with GP batteries. I'm sorry, but until now, I didn't have any real event shots.
I can say, that it works excellent for fill flash. For me, Canon's system with combination of ambient and flash exposure is fantastic. Set ambient exposure (for background) and set flash exposure (for foreground) and ... shoot. You can't always expect proper exposure, but hey, you are the boss of the camera. CHANGE setting if necessary! For fill flash I usually use A(perture) mode.
For inside (and darker) shooting I use M(anual) mode. I try to find as good ambient exposure as I can handhold it (sometimes ambient simply can't be enough bright), and then change flash exposure. My findings are that Canon can use more bright metering. In many cases (this is like in cloudy weather!) I found that flash exposure (when flash is the most important source of light) is too weak. Especially when there are reflective or white part of photo. Here is the example:
After this, I try to give FEC to +1 and I got this:
Because this was not enough bright for me, I tried with FEC +2 and then I got what I want:
Now white wall is white and colors on toys are vivid and clear.
This was with "average" flash setting. I tried with "evaluative" and it was a little better (FEC +1 with "evaluative" was very similar to FEC +2 with "average") . Until now I have used "average" - this was my old behavior and readings and I didn't changed it. Yes - until now, but now I will check on some different conditions.
Then I made almost hundreds of shoots with different settings and different lightnings. I can say that E-TTL II did all to not highlight any part of photo. But flash exposure was always in range of my expectation.
And there is two more things to mentioned:
- AWB is very good when using flash,
- AF with central point is very good and quick in low light.