What AF do you use for larger group photos?

[AMOMENT]

I have the Nikon D7000 and often shoot in AF-C, and toggle just one AF point at a time and positon on eyes for one subject. I know this question has been asked before to some degree, but I want to specifically ask it in regards to the D7000; which has 39 AF points, all of which can be selected at one time. Would you shoot either AF-S or AF-C and select all the AF points that seem to cover the span of people/family? Or, which seems to work out terribly for me, shoot in either AF-S or AF-C and still select only one AF point, and position it on the eye of the person closest and centered?

I recently practiced on a family. I shot with an aperture of f4 on my 50mm, from about 15 feet away. This would give me roughly about 4.43 of feet of DOF, which resulted in out of focus people. (I positioned them tightly together too) I wanted to throw my background out of focus and often see people's settings, photographing a fam of 4, even using an aperture of f/3.5, and having everyone tack sharp but background nice and soft. (I doubt they are more than 20-feet from them)

 

[mjhoward]

Sounds like you may need a Fine-Tune AF adjustment if you've got a DoF of 4.5' and still can't get a few people closely together in focus.

 

[MLeeK]

Focus falls 2/3 behind the focus point and 1/3 in front.
Single focus point locked on the person center front unless they are several rows deep.
I use a rule of thumb of the aperture should be equal to or greater than the number of people in the image after hitting f/4 or so.
So if you have 5 people-probably f/5.6. 8 people f/8. It works pretty well. Not any scientific reason, just seems to work OK. If I KNOW I have a pretty spread apart group I'll bump the f/ up quite a bit. you are better with too much DOF than too little

 

[KmH]

For shots of subjects that are moving very little, use a single focus point and AF-S focusing mode. Just make sure you have sufficient shutter speed that camera shake and slight subject movements are stopped (1/100 minimum for people portraits).
The camera can only focus on 1 point at a time, regardless how many focus points are activated.

Focus is only tack sharp at the point of focus. Focus sharpness immediately begins falling off in front of and behind the point of focus. How quickly sharpness drops off is what controlling the depth-of-field is all about.
So with your settings the 4.43 feet of DoF was distributed 43% in front of (1.9 feet) and 57% behind (2.54 feet) the point of focus. So where did you have the point of focus relative to the 4 people? The best place would depend on how the 4 people were posed.

DoF distribution is usually closer to 50/50 than to 33/66.

You do not say if you were shooting inside or outside, how the people were posed, how far behind the point of focus the background was, nor if you had room to shoot from further back so you could have used a longer focal length.

 

[orb9220]

Yep and guessimating distance to subject is critical for Dof calculation. As if they where more like 10ft away then you had under just 2ft for Dof. Any Group shots I start at f5.6. And after having them in position at 15ft. I will stand to the side of them. Raise my arms straight out to my sides is about 6ft. And see if they all fall into that arm width which at f5.6 is 6ft. dof. At 10ft that would be half of that.

Also I only shoot AF-S as allows me to pick and lock on my focal interest. Then recompose shot. For people I try to shoot 1/250th or faster as even standing still people make micro-motions that translate to less sharp.
.

 

[AMOMENT]

Thanks guys! Very helpful! Well, this was a family of 4. I shot at f/4 (MLEEK I actually remember you telling me that =) ) from about 15 feet away. However, I guestimated. For one example, they were sitting completely in a row, pretty close together so I figure they were on the same plane of focus. =( Some of the others were positioned as such: I had mom and dad back to back, sitting, and kids in front lying on their bellies sort of diaganal.