White spot in video shot with GL1 at DVinfo.net

David Hays · August 14th, 2003, 11:35 PM

I recently purchased a used GL1. When I play back video shot with this camera, there is a white "spot" just left of center. It's hard to determine the exact size, but it appears to be more than a single pixel. On a TV it appears to be three or four pixels wide. On a 19" LCD, it appears to be about a 4x4 block of white pixels.

Using the 19" LCD panel, I shot 20 seconds of video with each a red, blue, and green background. In each case the pixels are white. In other words, it doesn't seem to be just one CCD, but all three. That seems impossible, but despite the 3 CCD's, the 3 images obviously have to come together at some point, so I'm thinking the problem might not be the CCD's, but some other component in the camera.

If the spot were black, I might suspect some particulate on the optics, perhaps the prism, but I don't see how this could cause white pixels.

I need to verify this but I believe the size of the spot remains constant regardless of zoom, so this, and the fact the spot is white rather than black, rules out anything on the lens.

One other note. I have only shot low light stuff so far, aperature wide open and longish shutter speeds. I don't know if this is germane, but I thought I'd throw that in just in case.

Any ideas what might be the cause of this?

David

Ken Tanaka · August 15th, 2003, 12:02 AM

It sounds like you have some dead pixels in your CCD block. This is a very bad problem that will require an expensive trip to Canon service. Since you bought the camera used you may just be out of luck with respect to recourse or warranty.

Sorry to break the bad news to you.

David Hays · August 15th, 2003, 12:04 AM

The white spot is of constant size, regardless of zoom or focus, so it's definitely not any foreign material on the optics, and the spot is there regardless of the color of what I am shooting, so that seems to indicate it's not a problem with the CCD's. I'm guessing it's a flaw in the memory where these three images converge.

Anyone know a Canon tech I can call to verify my conclusion and find out what this might cost to repair? Guess I'll check out the Canon web site for repair locations.

David

Alex Knappenberger · August 15th, 2003, 12:31 AM

Well, it's not the CCD's, as Ken says, it's most likely in the CCD block (the prism), which is in front of the ccd's, and splits the light up. BUT! I could just be totally talking out of my *** and be completely incorrect. :D

I feel bad for you, that sucks big time. It's probably impossible to mask that too.

This is the risk in buying used equipment though.

David Hays · August 15th, 2003, 12:44 AM

I'm guessing it's something in the electronics rather than anywhere in the optical path, including the prism. If it were a problem with one CCD, I'd expect the pixels to have a color rather than being white regardless of background color.

David

David Hays · August 15th, 2003, 07:09 PM

I called Canon factory service today and they said they could not quote me a price for the repair until I had shipped them the camera, but with some prompting did say "at least $400".

The good news is that my seller is standing behind her auction and has agreed to refund my money. She had never experienced any problems with the camera (or so she says, but I believe her), so it's just one of those bad things that happen sometimes to good people. She is in the LA area, so will find someone to repair it and resell it. That's the right thing for her to do since the camera was "Mint Condition", but how many sellers would do that? I would, but I know I am "exceptional" :-)

David

August 14th, 2003, 11:35 PM	#1
David Hays Tourist Join Date: Aug 2003 Location: Wichita KS Posts: 4	White spot in video shot with GL1 I recently purchased a used GL1. When I play back video shot with this camera, there is a white "spot" just left of center. It's hard to determine the exact size, but it appears to be more than a single pixel. On a TV it appears to be three or four pixels wide. On a 19" LCD, it appears to be about a 4x4 block of white pixels. Using the 19" LCD panel, I shot 20 seconds of video with each a red, blue, and green background. In each case the pixels are white. In other words, it doesn't seem to be just one CCD, but all three. That seems impossible, but despite the 3 CCD's, the 3 images obviously have to come together at some point, so I'm thinking the problem might not be the CCD's, but some other component in the camera. If the spot were black, I might suspect some particulate on the optics, perhaps the prism, but I don't see how this could cause white pixels. I need to verify this but I believe the size of the spot remains constant regardless of zoom, so this, and the fact the spot is white rather than black, rules out anything on the lens. One other note. I have only shot low light stuff so far, aperature wide open and longish shutter speeds. I don't know if this is germane, but I thought I'd throw that in just in case. Any ideas what might be the cause of this? David

August 15th, 2003, 12:02 AM	#2
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	It sounds like you have some dead pixels in your CCD block. This is a very bad problem that will require an expensive trip to Canon service. Since you bought the camera used you may just be out of luck with respect to recourse or warranty. Sorry to break the bad news to you. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

August 15th, 2003, 12:04 AM	#3
David Hays Tourist Join Date: Aug 2003 Location: Wichita KS Posts: 4	The white spot is of constant size, regardless of zoom or focus, so it's definitely not any foreign material on the optics, and the spot is there regardless of the color of what I am shooting, so that seems to indicate it's not a problem with the CCD's. I'm guessing it's a flaw in the memory where these three images converge. Anyone know a Canon tech I can call to verify my conclusion and find out what this might cost to repair? Guess I'll check out the Canon web site for repair locations. David

August 15th, 2003, 12:31 AM	#4
Alex Knappenberger High School Student Join Date: Apr 2003 Location: Canton, Ohio, USA Posts: 609	Well, it's not the CCD's, as Ken says, it's most likely in the CCD block (the prism), which is in front of the ccd's, and splits the light up. BUT! I could just be totally talking out of my *** and be completely incorrect. :D I feel bad for you, that sucks big time. It's probably impossible to mask that too. This is the risk in buying used equipment though.

August 15th, 2003, 12:44 AM	#5
David Hays Tourist Join Date: Aug 2003 Location: Wichita KS Posts: 4	I'm guessing it's something in the electronics rather than anywhere in the optical path, including the prism. If it were a problem with one CCD, I'd expect the pixels to have a color rather than being white regardless of background color. David

August 15th, 2003, 07:09 PM	#6
David Hays Tourist Join Date: Aug 2003 Location: Wichita KS Posts: 4	I called Canon factory service today and they said they could not quote me a price for the repair until I had shipped them the camera, but with some prompting did say "at least $400". The good news is that my seller is standing behind her auction and has agreed to refund my money. She had never experienced any problems with the camera (or so she says, but I believe her), so it's just one of those bad things that happen sometimes to good people. She is in the LA area, so will find someone to repair it and resell it. That's the right thing for her to do since the camera was "Mint Condition", but how many sellers would do that? I would, but I know I am "exceptional" :-) David