View Full Version : XL2 Back Focus


David Stollak
October 3rd, 2004, 10:53 AM
Hi All,

Just got my new XL2.
I am noticing a back focus problem with the 20X lens and 3X lens.
I taped a newspaper headline accross the room.
I zoom in and focus. When I go wide, its soft and have to rack it into focus. With both lens.
Is there an adjustment on the lens that I dont know about?
Or is it done in camera?
Or is it adjusted by Canon?
Thanks in advance for your help

David

Rob Lohman
October 3rd, 2004, 10:59 AM
Backfocus is not consumer adjustable on those lenses. If it really
is a back focus issue they will need to go to Canon. I would
include the camera as well so they can see/test it.

David Stollak
October 3rd, 2004, 11:16 AM
Is the adjustment done on the lens or on the camera ?

Jeff Donald
October 3rd, 2004, 11:22 AM
The adjustment is done on the lens. But for maximum compatibility it is best to send in the camera and any additional lenses for the camera at the same time.

David Stollak
October 3rd, 2004, 11:25 AM
Thanks so much!

Don Palomaki
October 4th, 2004, 03:48 AM
Can't speak to the XL2, but with the XL1 andn auto lens, back focus adjustment is set electronically with values that are progammed into the body's memory. Thus a back focus issue could be caused by an error/problem in the camcorder with the stored value, the CCD-to-mount distance, the temperature compensation values, or the lens being out of spec.

Thus it is best to return both to have it resolved, and it is always good to send Canon service a complete description of the problem, along with a tape showing the problem

David Stollak
October 4th, 2004, 04:39 PM
Thanks again!

Alfredo Castil
October 7th, 2004, 01:54 PM
I just got my XL2 and the first test I did was the backfocus, I had no troubles. Thanks to all of you to address this problem and hopefully it was fixed in subsequent batches of the XL2

Rob Lohman
October 10th, 2004, 06:54 AM
Alfredo: it is not a "bug" in the system or something. Backfocus
can change due to certain elements like heat/cold etc. and might
require some re-calibration after a while.

David Stollak
October 23rd, 2004, 04:44 PM
Well,

I returned the XL2 and got a new one.
I still have the back focus problem with the 3X lens (manual focus).
I called Canon and they said to send them the camera and the lens, which I did.
They returned it to me saying "Checked back focus on 3X lens,
compared to factory3X, no difference found".

There is a definite problem with manual focus.
Obviously the camera is flawed.

Chris Hurd
October 23rd, 2004, 04:48 PM
Your best bet David is to return the camera and get your money back while you still can. Sounds like you still have a window of opportunity with your dealer there.

Dave Speace
October 26th, 2004, 10:16 AM
Just wanted to say and/or ask if you are focusing by zooming in all the way and pushing the button to focus and then zooming out to check the back focus...? If you are focusing using the focusing ring and then zooming out... it will go soft. Remember to focus using the button! Hope this helps.

tx, Dave

David Stollak
October 26th, 2004, 01:23 PM
Dave,

Thanks for your input,

I am zooming in and focusing using the focus ring, then zooming out. By using the button, are you refering to the AF button on the lens?

Doesn't that defeat the manual focus aspect?

David

Dave Speace
October 26th, 2004, 04:56 PM
Yes... use the button to focus with and see if the camera stays in focus when you zoom out!


Dave

Don Palomaki
October 26th, 2004, 05:58 PM
Try put up a resolution chart to check backfocus. If back focus is OK, the number of lines you can resolve in a picture width should remain about the same regardless of zoom setting. With the 3x telephoto, you may be able to resolve 1" lines at a given distance when at full xzoom. At full wide the lines would have to be 3" wide to appear equally as sharp.