Nikon 12-24mm back focus?

I've noticed what I think is a back focussing problem on my Nikon 12-24mm on

the D300. I've posted a recent example, but have noticed a similar trend on

other images. Other lenses seem ok.

 

Focus is on the subject's left (closest) cheek. The subjects left eye (closest)

is slightly out of focus, whereas the right is spot on. This only seems to

happen wide open (f4), at 24mm, at close focus. It didn't happen (or maybe I

didn't notice...) on the D200.

 

So do you think this is a back focussing problem? the examples I've posted are

unsharpened straight out of the camera. All I've done is convert the RAW file

to JPEG's. The crops are 100%.

 

Thanks for any help...<div></div>

Here are the crops. Thanks<div></div>

Crops..<div></div>

You need to compare the same situation on both cameras to be sure. With a static subject

probably.

 

But I have to ask why you'd shoot wide open if you want both eyes in focus?

Depends on your F-stop If you were shooting wide open and the depth of field was shallow, the way her face is turned the right eye could be in focus while the left is soft.

Thanks for the replies;

Peter; It was dark and to keep the shutter speed up had to shoot wide open. I also didn't want to use a high iso, and also only had about 5 mins to take the photo for an article I was writing...

 

Wayne;I thought of that too but the focus was on her left (front cheek) by the unsharp image. I'll post another example.

 

In the next pics the focus was on the front of the glasses (left eye), yet the right (rear) eye is in focus.

 

I have just done an experiment where I've pulled the fine tune forward by -5 and it seems to have worked. So i might have wasted everybodies time... :-( sorry....<div></div>

Here's the crop<div></div>

When I test, I usually, put a battery on my desk and shoot wide open and get as close as I can to the battery (with the lens/camera).

 

 

You sure its not the camera? Tried with other lenses? Fast enough shutter you don't need tripod.

If it's a back or front focus,the D300 brings the possibility to look for by an acurate way the correct focus for some AF lenses,please see the chapter manual "configuration menu" ,Sorry by I don't have the manual in English.

Regards

Thanks everyone. Just did a full test & got it sorted;

 

The 12-24mm needed -10 and is spot on now. I tested the 20mm f2.8 AFD and it needed -15. My 50mm f1.8 and 180 f2.8 were spot on.

 

Cheers