Back Focus?

Trying to figure out what's going on with 7D and Sigma 120-300 combo. Is it the camera or lens?

Not getting the results I'd hoped for.

Can anyone tell me if this is a back focus issue. Fosus point is right on the hip of the girl in the pink about to kick the ball.

Both of the other girls seem to be sharper though.

Photo?

rrblint wrote in post #15177362
Photo?

+1

Were you using spot focus or zone focus?

2n10 wrote in post #15177370
+1

Were you using spot focus or zone focus?

Spot focus.

Ok I see it now...Focus looks pretty good though I agree that the young lady in the back is slightly better focused than the one in front.

Were you using Servo?...Are you sure your focus point didn't slip off of the lead player?...Looks like the action was pretty fast.

Yes, I was using Servo and yes I check the focus point in camera and it is solidly on the hip of the girl about to kick the ball.

Here is the link to the "focus sticky":

https://photography-on-the.net/forum/showthre​ad.php?t=857871

And here is one dealing specifically with front and back focusing:

https://photography-on-the.net/forum/showthre​ad.php?t=10526

I would advise you to study these threads carefully and follow the recommendations that you find there.

rrblint wrote in post #15177413
Here is the link to the "focus sticky":

https://photography-on-the.net/forum/showthre​ad.php?t=857871

And here is one dealing specifically with front and back focusing:

https://photography-on-the.net/forum/showthre​ad.php?t=10526

I would advise you to study these threads carefully and follow the recommendations that you find there.

Just hoping to get some opinions of what I posted. If that's not possible I do understand.

Thanks for the links anyway though.

You don't want to use spot focus for action shots

To answer your original question, back focusing is a result of the combination of that particular camera and that particularly lens, not exclusively one or the other. The lens' motor shifts the focus and the camera tells the lens when to stop. The lens might not be stopping exactly on the right spot and the camera may need to tell it to stop earlier or later. That's what MFA does.

TeamSpeed wrote in post #15177646
You don't want to use spot focus for action shots

Sorry, center point not spot.

jdouglas003 wrote in post #15178037
Sorry, center point not spot.

Hate to hijack the thread but are you saying NOT to use center point focus for sports/action but "zone" (for lack of a better term i.e. multiple focus points)?

no.
dont use spot focus as it is a slower type of focus and not suited for action like this.
center point is fine.
zone may or may not be better.

Ltdave wrote in post #15178208
Hate to hijack the thread but are you saying NOT to use center point focus for sports/action but "zone" (for lack of a better term i.e. multiple focus points)?

No, the original reply said "spot focus", and spot focus is not the fastest (that mode trades speed for accuracy) for sports/fast action. I use manual point with expansion most of the time.

What was the exposure time set to? 1/8000?