how to achieve DOF for group pictures?

[sgogula]

Hi,

Is it possible with Aperture 2.8 to keep everyone in focus in group pictures?

I use rebel xti, I tried with focus points but it chooses itself and will not allow me to select all focus points.

Is there any technique to achieve this?

Thanks

[John_B]

sgogula,
I suggest you put your equipment in your signature line so we can know what you are shooting with ;) As we don't know what lens you are using, focal length also has an impact on DOF

Using MF (manual focus) will help you select the focus point ;(

Here at DOFMaster <-- click to see (http://www.dofmaster.com/dofjs.html) you can figure out just how much DOF you can get with an aperture of f/2.8 It will also show In front of subject and behind subject that will be in focus.

[BradM]

I believe what you are saying is that when you select all focus points to be used in a group portrait and when you partially depress the shutter that only one or two points will light up as achieving focus. Dependent on the mode you are shooting in, this would be normal focusing behavior.

I have never used the A-Dep setting (I perfer to think more than the camera does) but is my understanding that the A-Dep mode will "look" at all parts of the scene under the focus points and choose the appropriate aperture to have everything or everyone under the focus points in focus. This of course in lower light or any real depth in the posing of the subjects may well lead to the use of an aperture than you would prefer not to use for a number of reasons.

This leads to your other question about using a wide/fast aperture like f/2.8 to capture a group portrait, it is possible but to do so all of the subjects must fall within the limited dof that is available at this f/stop or any other aperture chosen for the composition. This may mean that all of the subjects be posed all but perfectly parallel to each other, in a group of more than three this may not be possible nor even the most attractive pose. The suggestion to use a dof calculator is a very good one.

Knowing or understanding the dof available for the particular body, lens, subject distance and aperture chosen is a vital first step to achieve the particular look of an image the photographer is trying to capture. From that point knowing then the dof one can concern themselves with the posing and the specific exposure requirements required to capture the image theyt envision.

[sgogula]

sgogula,
I suggest you put your equipment in your signature line so we can know what you are shooting with ;)

Thanks for your the link,I shall go through that and updated my signature aswell.