Need advice on focusing

[SandraD]

Hi all,

I need your advice on focusing ;) and have two questions to ask.

1. When shooting a group of people (family portrait in my case) do all AF points need to be lit up to get the perfect focus on everyone?

2. If so, what am I doing wrong? When shooting more than one person I can only get one AF focus point to light up.

I shoot with a Rebel XT and only a few days ago received my EF 24-70mm 2/8L lens.

Thanks in advance everyone!

~Sandra

[Mike]

What aperture are you using? In Av try a smaller aperture for a greater depth of field. It depends on who's standing where as to whether they will all be in focus.

If all else fails, try A-Dep . What that does is select an aperture for you that will get everything covered by the focus points in focus.

For assistance in working out what depth of field youwnat and the aperture you need look here: http://www.dofmaster.com/dofjs.html

[Mike-DT6]

Welcome to the forum Sandra :-)

Remember that there is a plane of focus, so everyone the same distance from the camera as the confirmed/lit AF point will be in focus.

Mike

:-)

[JeffreyG]

Hi all,

I need your advice on focusing ;) and have two questions to ask.

1. When shooting a group of people (family portrait in my case) do all AF points need to be lit up to get the perfect focus on everyone?



No, there is only one flat plane where the camera is in perfect focus. If you see more than one AF point light up it is only because they are coincidentally laying on things that happen to be exactly the same distance from the camera, so both are at exactly the plane of focus.


2. If so, what am I doing wrong? When shooting more than one person I can only get one AF focus point to light up.


Stop letting the camera pick the AF point to use. It is not smarter than you, and you are the person that knows what you want in focus.

I shoot with a Rebel XT and only a few days ago received my EF 24-70mm 2/8L lens.

The biggest thing to understand is that the smaller the aperture (higher #) you select the fatter the area in front and behind that one plane of perfect focus where things will still look acceptably sharp. If you are shooting that 24-70 wide open at f/2.8 you may not have enough depth of field to make everyone sharp.

Try putting the camera in Av mode and select an aperture of about 8.0. Focus on someone in the middle of the group (front to back) and take a picture like that. Be carefull of your shutter speed as you select a higher aperture number. Higher numbers let in less light and may need a higher ISO also selected to keep the shutter speed high enough to prevent blur.

Thanks in advance everyone!

~Sandra

Welcome to POTN.

[tonybear007]

Sandra welcome to POTN.

I concur with what has been said. Depending on what focal length you are using on the 24-70mm lens you, you are more likely to get all persons in the scene in sharp focus with f/8 or f/11 than with f/4.0 or f/5.6.

Also consider that sometimes it may be better to have 2 or 3 rows of people rather than placing all of them across from left to right in the scene.

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EOS 3 (35mm film), EOS 40D, Canon 24-70mm f/2.8L, 70-200 f/4L, TAMRON SP AF17-50mm f/2.8
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