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-   -   XL1 / XL1S focus hunting backfocus problems (https://www.dvinfo.net/forum/canon-xl1s-xl1-watchdog/31-xl1-xl1s-focus-hunting-backfocus-problems.html)

Bob Safay September 3rd, 2003 07:49 AM

I just sent my XL-1s in for a check up. I was experiencing the same problem. I was also told that the 3ccd chip may be a little out of alienment. I will let you all know what the results are. Bob Safay

Julian Cauceglia September 11th, 2003 07:29 AM

Focus Problem XL1S
 
In attempting to film a moon-set, my XL1S using standard 16X ISII lens, I find the focus moves in and out. After reading about similar problems I tried turning off the auto-stabilize and auto-focus, but it still happnes. Is it possible my lens is defective? Or is there something I missed to correct this problem.

Thank you in advance for your help.

Rob Lohman September 11th, 2003 08:51 AM

In what shooting mode were you? If you are in green box easy
shooting you can't turn of those things. Make sure you are in
full manual mode.

Ken Tanaka September 11th, 2003 10:03 PM

Also make sure that you are in Manual Focus mode.

Don Palomaki September 12th, 2003 04:31 AM

Auto focus may have difficulty finding and holding focus if the lighting level is low, below ~50 lux.

Alan Van Vliet November 21st, 2003 05:26 AM

High speed tennis with auto focus lense
 
I have read quite a few comments on the auto focus problems of the standard auto focus lense for the XL1S. (16x Zoom XL 5.5-88mm IS II)

Any suggestions for shooting instructional tennis videos from a varying distance of 40 - 50 feet and from 20 -50 feet.

The focus quite often begins to "hunt" right at the critical moment when the player makes his last move toward the ball just prior to contact.

Any suggestions would be greatly appreciated.

Thanks in advance.

AL

Jeff Donald November 21st, 2003 06:39 AM

Similar requests have been made in the past. Unfortunately some sports activities are not well suited to auto focus. It may take some practice, but you'll have better success in manual focus.

The AF in most, if not all, prosumer cameras is not up to the job of tracking fast motion.

Rick Bravo November 23rd, 2003 11:20 PM

Alan,

The Canon auto lenses have a hard enough time trying to hold focus on a stationary object, much less a fast moving one.

You might consider the 16X manual lens. It makes a world of difference.

RB

Mark Solleveld January 5th, 2004 02:15 PM

Focus critical but not critical
 
Hi all,
been reading for hours now.. but I'm afraid I couldn't find this problem:

I have a XL1, everything manual...

Zoom in on the back focus card. Get focus. Zoom out. The card is still sharp. But if I then put my hand in front of it (a feet or more away from the lens), my fingers are NOT sharp.

So you could say this is a back focus issue, but during the zooming out the chart stayed sharp. Critical focus doesn't seem to work? I used to shoot all the time all zoomed out and everywhere I went it was all sharp. But that was with another XL1..

Also, if I put a little force in my hands I can tell that the lens moves/seems a veeeeery little bit loose in the body. You can see a little bit of silver metal from the lens mount (more on 1 side then on the other side from the connection). Does everybody see a little bit of the mount or is your lens extremely tight to the body?

thanks all,
Mark

Jean-Philippe Archibald January 5th, 2004 02:26 PM

Hum... The behavior you are describing seem normal to me. You have focused on an object (in this case the card), zoomed out, and put another object (your hand) nearer your lens. The distance between the two objects explain your focus "problem". This is called the "Depth of field". There is some things you can do to increase the depth of field, like closing a bit more your iris (an higer f number).

Hope this help,

Mark Solleveld January 5th, 2004 02:54 PM

Maybe I told it the wrong way..

I zoom in.. get the focus. Then I zoom out (which on 80% or so goes out of focus and then into focus again btw) and the chart seems sharp. But then.. when I walk towards the chart, it gets out of focus again. Keeping it all zoomed out of course...
I think it's supposed to keep focus walking towards the chart zoomed out, not touching the zoom. I'll try your DOF thery tomorrow when I have a bit more light, but I'm seriously having doubts..

thanks again,
Mark

Rob Lohman January 5th, 2004 04:14 PM

Are you PHYSICALLY moving the camera after you set the focus?
If so you are also moving the focussed area and you might get
things out of focus if your lens is quite open. The more open the
lens, the less DOF.

BUT, it could be an issue with the lens itself indeed. But I'll leave
that to the lens professionals here on the forum.

Mark Solleveld January 6th, 2004 02:32 AM

Yeah.. moving it physically..
You know like when a presenter of the show you're taping suddenly approaches the camera, or wants to show his teeth or something. Shouldn't be a problem being all zoomed out normally..

Rob do you maybe know a good company in The Netherlands that can have a look at it? Or do you know the Canon repair-price (outside guarantee)..?

thx

Jean-Philippe Archibald January 6th, 2004 08:39 AM

Your camera is not broken. Whenever you change the distance between the camera and the subject, the focus will change also. Workarounds are to focus while moving, or to try to increase the depth of field enough.

Rob Lohman January 6th, 2004 08:57 AM

I'm suspecting it isn't broken either and you are probably just
"seeing" it the wrong way, or we are understanding you wrong.
With that being said, I didn't notice you were from the wetland
as well. If you want we might be able to meet up some place
and I can take a look at your camera? See if I see anything
weird?


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