Help with 7D AF

[photog1107]

I am not sure if this is the right place to post, but since this forum deals with Canon, I figured some 7D users might have insight into my recent problem.

Just got my new 7D and within days took the family Thanksgiving portrait. I set it up on a tripod, with exposure set for 1/60th, f/4 and 1250 ISO, and 50 mm. Had a flash that I bounced to eliminate shadows. I thought all was well until afterward in processing, I see the focus is way too soft... practically out of focus.



The only thing I can figure, after much subsequent testing, is that I had it set on the 19 pt AF mode (AI Focus), versus the single point focus. I thought that 19 pt would have been the correct option, since i had multiple people involved. But in my testing, I see that for still subjects, the 19 pt is much less accurate. I have had great success using 19 pt for sports, incidentally

Can anyone tell me if my conclusion on "what went wrong" seems valid? I think from this point on, I will save the 19 pt focus for sports and use single point for still subjects. Does that sound right? Any further insight would sure be appreciated.

[OsmosisStudios]

It's not the mode you were in: the camera didnt AF at all. Its focused far off the plane. The multi-point AF modes take longer than the single points to lock focus, so that may be the issue.

[photog1107]

I also forgot to mention I used the 10 sec self timer, in case that has any additional bearing.

[ddr]

just a side note, isn't f4 a little big for that many ppl?

[Sime]

Issues off hand : f4 and maybe bring your shutter speed up a touch.

f8 and 1/125th with flash may work a little better.. f8 giving you a bit more depth of field perhaps? (depending on your focal length)


Sime

[Sime]

When I popped into your flickr / full size - I see lots of noise, too... makes the focus look a lot less sharp, but I stick by f4 being a bit shallow and 1/60th being a touch slow.. Get as close as you can without messing up your framing to help your flash - drop the iso down a bit (Turn every light on in that room) and see how you go - or, take 'em outside in the sun (unless you're in England where there is NO sun...)

S

[daft_biker]

I think I see 2 problems - the focus is too far back as the painting looks sharper than the faces. Manual focus should sort that but I agree f/4 is likely to be cutting it fine DoF wise.

There looks like what might be hints of camera shake too. Was mirror lockup used?

Also, it might be worth trying the ISO settings to find out if the full stop values show less noise than the intermediate settings - i.e., is it better to go straight from ISO 800 to ISO 1600 than using ISO 1250.

[CaptainNH]

As Osmosis said, it appears that your 7D didn't AF correctly.

By my estimates, from your EXIF and assuming you were at about 7m, you should have had a little over 3m DoF, yet I can't see anything in frame that is in sharp focus.

f/4 should be ok for a group shot like this (though I would probably go smaller), but 1/60 is too slow.

I know you were using a tripod, but 1/60th isn't going to freeze any subject motion without a blast of flash. [Though you problem isn't motion blur either, unless you're in an active earthquake zone ]

How's your 7D focus in good light?

[photog1107]

Thanks so much to everyone for the valuable input.

In general, I have seen acceptable, if not great, results with the AF. Here is another shot taken during the same day. It's outside, handheld at 1/250th, ISO1000 and f 5.6 (WB is obviously incorrect). For purposes of evaluating the AF, there is a noticeable difference, with this one being much sharper.



I will take everyone's advice under consideration. I thought 1/60th would be fine, esp with a tripod, but while that may have been a factor, it appears that my AF simply did not perform correctly. Could the self timer have thown it off? This was an important family photo... I sure want to learn from this mistake!

[jdepould]

I never trust AF+self timer. In that instance, it's probably best to simply prefocus, flip to manual, then hit the timer. As far as what actually happened ... not sure really, it's not like it focused on the background.