Portrait Focus

[littleny]

Hi everyone,
from looking at this forum, it seems that out of focus shots are a common problem. my focusing is so inconsistent. when possible, i try live mode and manual focus then zoom in as much as possible. but i prefer to use auto focus..but its like a crap shoot (no pun intended).. my shots look great on my cameras viewer then ewwwww when i get them on the computer. Heres a sample.
FYI.. I use a single center point focus. set on single shot. I always lock on the eye. In this particular shot I used a shallow depth of field as i didnt want the building in the background to distract. I thought my 1/250 would be plenty fast enough but ???
you guys be the judge. Im including a link to the full size. much thanks.
test shot.jpg
All sizes | help me please | Flickr - Photo Sharing!

1/250 @ f2.5
50mm
no flash
iso 200
Canon Rebel xsi

[MrJones]

your problem is that you're using the central focal point when shooting in a narrow DoF (f/2.5).
what you are doing is locking the camera on the eyes and then MOVING the camera to include his entire body. while doing so you are actually changing the distance between what you focused on to the camera - hence throwing the eyes out of focus.
you camera lets you choose your focus points for a reason.
what you need to do in the case taking portrait photos like the one you've posted is set the focus point as the left edge and not the center. that way you'll be focusing of the eyes and still include all of his body in the photo with out moving the camera.
btw, when you're moving your camera - you are moving with your body, every movement like that takes you a bit back or forward which again - throws you out of focus.

good luck

[SusanH1970]

Try toggling your focus points instead of using the center point and recomposing. I think you'll see a big difference (for all the reasons MrJones pointed out).

[littleny]

your problem is that you're using the central focal point when shooting in a narrow DoF (f/2.5).
what you are doing is locking the camera on the eyes and then MOVING the camera to include his entire body. while doing so you are actually changing the distance between what you focused on to the camera - hence throwing the eyes out of focus.

wow...that never occurred to me and makes so sense...

so i guess in the future (esp with a narrow dof) my single focal point should be set to the closest point that i want in focus..therefore less movement.
thank you so much

[MzChristine]

That never occurred to me either.. can't wait to try this out later today!