5D mark II versus 7D spot focus

[PeterJ]

Thanks everyone for the feedback .

I don't think anyone has specifically addressed this issue.  If by 'spot AF' you mean that mode on the 7D, there is no such mode on the 5DII.  With Spot AF, the AF system reduces the effective size of the AF points.  Most people aren't aware that the actual AF point is significantly larger than the little box that represents the AF point in the viewfinder.  That's one thing that leads to complaints about AF - you place the box right on the small feature you want to focus on, but the actual AF point is larger, and if there's a high-contrast feature that's just outside of your selected AF point 'box' the camera will lock onto that instead of what you put the box over.  The 7D's Spot AF restricts the region of the AF point used to an area approximately equal to the size of the box in the viewfinder (note: not the tiny inner box that indicates Spot AF, but rather the larger, main AF point box). 

That I didn't realise and probably isn't something I'd enjoy, as the article you linked mentioned focus and recompose does have some things to be wary of but I've always preferred the 7D spot mode over single-point. Having said that I'm sure it's something I'd get used to and just a matter of knowing the limitations.

Back to my statement above.  The center AF point of the 5DII does better in low light than the center AF point of the 7D.  With the center point, my 5DII will get an AF lock in lighting conditions so dim that the 7D would hunt and give up.  With a Speedlite mounted, the AF assist comes on sooner and more often with the 7D than with the 5DII.

I presume you avoid the AF assist on the 7D because the strobing of the popup flash is annoying - I know that's the case for me.  You might consider using a Speedlite - you can set it so the flash doesn't fire, only the AF assist lamp does, and the AF assist is a much less offensive red grid (just be sure to get one with the dedicated lamp, like the 430EX II - lower flashes, e.g. 270EX II, just strobe the main tube like your popup flash).

Hope that helps...

I agree the popup is vastly annoying. I've got a 580EX II and do find the AF assist beam is good, but for some shots prefer them to be candid rather than that "oh look we're about to have out photo taken" look that you always end up with using AF assist. Anyway it sounds like for for those situations the 5D will win hands down, I was aware of all the IQ advantages in low light but didn't know how the AF held up there.

[PeterJ]

Just thought I'd post back and thank everyone for their advice, as of today I'm a proud 5D Mk II owner . I haven't had a chance to take any especially interesting shots but gave it a test under varying conditions and I can't find much difference in the center focus point speed / low-light perfomance versus a 7D. As some commented the outer spread of focus points is not great (well pretty bad), and I tried to repeat a shot I'd taken recently through a bird cage using spot focus that it couldn't match, but I expected as much.

Now for the good part is that banging on a tripod and taking a few food shots the colour reproduction was fantastic. Outside during the day the FF gave my 70-200 a much better focal range and shallow depth of field for the style of photos I often take. Got some nice shots at night too using a 50/1.4, I expected a nice ISO boost but it seems to handle dramatic changes in contrast much better too. I'm a happy camper and look forward to giving it a good run over Christmas. It will really complement my 7D well rather than replace it .

About my biggest gripe so far is the location and type of power switch, I saw a post recently by someone asking about how to extend the standby time. I didn't reply but thought why can't you just turn it on & off between shots but now see where he was coming from. I put mine of a tripod earlier and just about needed a screwdriver to get at the switch .

[Cyclops]

I just got my 5D a few weeks ago, and comparable the button layout (power switch) is much better on the 7D.  Took me a long time to find the quick menu on the 5DIII, and takes a while to activate, and that menu is why i like my 7D.