Group shot, all faces focused help?

[Michiyo-Fir]

I rarely ever do group shots but sometimes I get asked to do a few for people's parties and such.

I have a problem with focusing in large groups. I can set my camera to all points auto-focus but it often focuses on weird spots like people's chests, arms, etc.

When I use single point area focus, I can focus very nicely on one person's face but the rest of the people's faces end up not as sharp and in focus.

How can I make sure everyone's faces are focused?

 

[ChefStaller]

*im a newb warning
As far as I can gather its going to be a depth of field issue if they are not lined up perfectly, so if other faces are comming up blurry besides your main subject , make your aperture number larger (actually making the aperture smaller) and you will get more in focus.

 

[Big Mike]

It doesn't matter how many focus point you are using...the camera can only focus on one 'plane'....a specific distance from the camera. Anything that is that far away, should be in focus.

The way a camera works, we have what is called the Depth of Field (DOF). This is the range of distance, around the focus point, that will also be in focus for your photo. So for example, if your DOF is 5 feet deep, anyone in that range should be in focus.

There are several factors that determine DOF. The primary way we control it, is with the aperture of the lens. The smaller the aperture (higher F number) the deeper your DOF will be. The larger the aperture (lower F number) the more shallow your DOF will be. For example, at F2, you will have a shallow DOF and at F8 you will have a deeper DOF. So for a group shot, you would probably want to shoot closer to F8, than F2.

Focal length and distance to subject will also make a difference. The closer you are to your subjects, the shallower your DOF will be. So when shooting a group, back up a little bit and it can help to give you a deeper DOF.

Also note that the DOF extends 2/3 past your focus point and 1/3 back toward the camera. So when you are shooting a group, try to focus on a point that is near the front of the group, and not near the back.

 

[Michiyo-Fir]

Thanks guys. I do understand the concept of DOF.

For the shots I took I tried to use quite a small aperture but I guess since it was a very large group shot (25-30 ppl) some people were just too far behind...

One more question. If I wanted to do a portrait style shot of 2 people and wanted a nice bokeh in the background, is it possible to keep both faces sharp? For example if it's a mother and child or couple shot. Making the aperture too wide causes one person's face to be extremely blurry but making the aperture small ends up with a somewhat clear background?

 

[Flash Harry]

Then test your lens for each aperture from wide open to stopped down at a certain distance, if f4 at ten ft does the trick then use that, or, whatever you discover from a test, its not too hard a task as long as you have a camera/lens and a few objects at set distances from the lens. H

 

[Big Mike]

One more question. If I wanted to do a portrait style shot of 2 people and wanted a nice bokeh in the background, is it possible to keep both faces sharp? For example if it's a mother and child or couple shot. Making the aperture too wide causes one person's face to be extremely blurry but making the aperture small ends up with a somewhat clear background?

You can also look up a DOF chart for your particular lens & camera. That you could see that, for example...at 50mm, F4 and 10 feet from you subject...you might have 3 feet of DOF. So you would just need to arrange your subjects so that they fall into that DOF.

It's usually best to stop down when you're unsure, just to be safe.

Of course, the more you stop down (smaller aperture), the more in-focus the background will be. You can control this by moving your subject farther away from the background...because the farther away the background is from your focus point, the more out of focus it can get.

 

[hasan]

Thanks guys. I do understand the concept of DOF.

For the shots I took I tried to use quite a small aperture but I guess since it was a very large group shot (25-30 ppl) some people were just too far behind...

One more question. If I wanted to do a portrait style shot of 2 people and wanted a nice bokeh in the background, is it possible to keep both faces sharp? For example if it's a mother and child or couple shot. Making the aperture too wide causes one person's face to be extremely blurry but making the aperture small ends up with a somewhat clear background?

Actually the easiest way is to focus on one face and press your shutter half-way, then move you your camera so the focus is on the other face and then take the picture. You should do that at f2 or f4 to keep a nice bokeh.

 

[2WheelPhoto]

droid has an "excellent depth of field calculator" app

 

[KmH]

Bokeh is only tangentally related to DOF. Bokeh is not adjustable. Bokeh is actually the Circle of Confusion (CoC) a lens design produces.

 

[petahsumething]

thanks ********************

 

[Buckster]

Thanks guys. I do understand the concept of DOF.

For the shots I took I tried to use quite a small aperture but I guess since it was a very large group shot (25-30 ppl) some people were just too far behind...

If you're careful about positioning your background so that it would be okay for it to be in focus and not distract from the group shot, you can use hyperfocal distancing to get the whole group in focus. Just another option to think about.

 

[cgipson1]

you may find this useful.. and as mentioned above, there are also phone apps. Go to the App store for your type of phone and search for DOF or Depth of field, and you will find some. Online Depth of Field Calculator