View Full Version : backfocus problem


Bill Parker
February 15th, 2008, 07:31 AM
I've just discovered a focus problem - when I zoom in tight and focus and then zoom all the way out, the focus holds. If I zoom in tight again at all quickly (servo or manual), the focus is gone. It's fine if I zoom in slowly. I found a thread earlier: http://dvinfo.net/conf/showthread.php?t=111685 that talked about a backfocus procedure you could perform on the EX1's internal menus, but I couldn't find how to access them. Does anyone know how to do this?

Thanks.

Piotr Wozniacki
February 15th, 2008, 07:36 AM
Bill, what you're describing does NOT sound like a typical back-focus problem to me! Are you sure you're not in AF or MF* (manual focus assist) mode?

Anyway, here is the procedure:

1) Press and hold the "CANCEL" "SEL/SET" and "MENU" buttons simultaneously. The back focus is the bottom item in the Maintenance menu.

2) Point the camera at a back focus chart with the camera about 12' away from the chart.

3) Zoom in and focus.

4) Select "Auto FB Adjust"

5) Select "Execute"

6) The camera will zoom in and out and do an Auto Back Focus correction.

Of course, do it at your own risk. Please keep us posted!

Bill Parker
February 15th, 2008, 07:45 AM
Piotr,

Thanks. I just discovered my problem. I had MF assist on and it would lose focus after I zoomed out and went back in again. Once I disabled that, I was fine. Do you use the MF assist?

Piotr Wozniacki
February 15th, 2008, 07:56 AM
Piotr,

Thanks. I just discovered my problem. I had MF assist on and it would lose focus after I zoomed out and went back in again. Once I disabled that, I was fine. Do you use the MF assist?

This is what I suspected, Bill.

No, I don't use the MF assist - I prefer to have full control myself :)

Steven Thomas
February 15th, 2008, 08:13 AM
Yes,
don't use MF assist.