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Canon XL and GL Series DV Camcorders
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Old August 20th, 2010, 02:58 PM   #1
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Back-Focus???

Hello,

Iím uncertain as to my XL2 having a back-focus problem. After speaking with Canon extensively via phone, my only option now is to drive to their NJ facility (which is close to 90 miles each way), tie up the camera and probably pay for a diagnosis.

Iím about to finish the final shooting for a DVD project in a cyc studio. During the first phase of shooting I noticed that manual focus would go soft about 1/2 - 2/3 of the way to full wide after establishing critical focus using my human subjectís eye and toggling the auto-focus switch. Iíve also tried achieving critical focus at full zoom with the focus ring and it still goes soft approximately 2/3 of the way to full wide.

As Iíd prefer not to use gain above +0, Iím relegated to a 2.6 aperture to achieve proper exposure at 60fps @ 60i (must be 60i Ė exercise video) in the studio lighting conditions. The reason Iím unsure about the back-focus issue is that I think the fairly wide aperture of 2.6 may be affecting the overall focus at full wide due to bokeh (shallow depth of field). When I shoot with say a 5.6 aperture, I donít notice quite the discernable softening I see at 2.6. I also have read that when shooting with a 1/3Ē chip camera one should stay at or numerically below f4.0 anyway Ė not that I have much choice.

Am I correct in surmising that the relatively large aperture is responsible for the softening of the focus at 1/2 - 2/3 wide or should focus stay sharp regardless of aperture?

Is this a back-focus issue or just a limitation of the XL2?

Thanks in advance.

Steve M.
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Old August 21st, 2010, 03:42 AM   #2
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It sounds like back focus, it's something that does need adjusted occasionally (or in the case high end HD lenses pretty often and it's done by the camera operator or DP on the set).

I don't know about this camera, but on other cameras it's possible to access menus so that the camera can run the back focus setting function. Someone may be able to tell you how to do this yourself.

Regarding Canon, it's something in theory they should be able to do this while you wait, if it's more serious then they can hold onto the camera. Of course, it's another matter if they wish to do so.
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Old August 21st, 2010, 05:53 AM   #3
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Brian,

Thanks for the input; from what I've read in a few posts here and elsewhere, the XL2 has no user-servicable back-focus adjustment; it's said to be an electronic adjustment Canon must provide.

I'm "all eyes" if someone knows how I may perform this adjustment myself and save a big drive and at least $150.00 bucks.

Thanks again for your help.

Steve M.
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Old September 18th, 2010, 08:11 PM   #4
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If the back focus (Flange back) adjustment on the XL2 is like the XL1, it can be set by a user who has a so called "Service Remote Controller," a modified Sony made RM-95 remote control that connects via a LANC cable. Canon Service tool DY901394-000. The settings are stored in the camcorder memory. The directions run several pages in the service manual and are not intended for other than skilled technicians. Again, that is for the XL1, not sure about the XL2.

The point of focus, once set, should hold through the zoom range, especially as you zoom wider, but a give object may loose detail and look softer because it subtends a smaller number of pixels in the image.
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Old September 30th, 2010, 09:50 AM   #5
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So as my XL1s is EOL'd, will canon still do service on my camera - I've tried calling the XL club, but they don't exist for the XL1 any more.

Where can I get the Canon service manual for my camera? Can mere mortals get hold of the service remote controller?

As I can't afford to upgrade at this point, how do I keep my current camera (and my nascent business) up and running?
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Old September 30th, 2010, 04:50 PM   #6
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Canon and others typically provide factory support a camcorder for about 7 years after it is EOL. I do not recall when the XL1s reaches that point (probably within a year or so at the most), but the XL1 passed it a while ago.

At one time you could order the manuals an controller from the Canon Parts number, but then Canon restricted the sale, perhaps because too many home handi-men were messing up the camcorder. At one time you had to sign a warranty release to get it. In any case that is where I would start. Also, some of the service manuals outlets might have it by now. The control is a standard Sony wired remote control with a simple modification to allow it to do the adjusting. There may be some old posts in the forums that give more detail on it.
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Old October 4th, 2010, 09:38 AM   #7
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Thank you :)
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