XL1 Issue...Strange!!! at DVinfo.net

Grady Anderson · July 20th, 2005, 09:27 AM

I'm having an issue with my XL1 which has me baffled. When I am recording from a tripod, or any other stable platform, and there is no motion in the frame, my picture looks great. But, once motion occurs, let's say someone walks into the picture, I am getting mosaic noise on just the part of the frame in which the motion is ocurring. The noise stays with the motion and all stationary objects remain clean. Does anyone know what thats all about? I have searched the web inside out.

Jimmy McKenzie · July 20th, 2005, 09:31 AM

Assuming you are 0 gain, no shutter effect, standard mode not frame mode, and your heads are recently cleaned and the tape is brand new, then likely the heads or the drum are in need of servicing. You've had the camera for 6? years ... has it ever made the trip in for servicing?

This sounds like a drum problem.

You might want to try a different lens just to rule out the possibility of a lens problem...

Greg Boston · July 20th, 2005, 09:45 AM

Unless he is seeing this in the v/f live while in pause mode. In which case, the camera has a serious malfunction and needs to be sent in for repair. The viewfinder doesn't show what's recorded to tape when recording.

-gb-

Grady Anderson · July 20th, 2005, 10:40 PM

That is correct, I do not see the noise in the viewfinder, only in playback. 0 gain, no shutter effect, standard mode not frame mode, and my heads are recently cleaned and the tape is brand new. I purchased this camera second hand and I have owned it for about 1 year. I have not sent it in for servicing before. How much does something like that cost?

Greg Boston · July 20th, 2005, 10:53 PM

Sounds to me like you might have a DSP chip gone bad. Since you don't see this problem in the v/f except during playback, it's tough to figure out just where the bad data is entering the record stream (electronics, or tape transport). Have you by chance tried playing back some of that footage on another mini DV device? That would help narrow it down for the Canon folks if the recorded tape plays fine on another deck or camcorder.

Tough break. I don't have any idea what kind of cost to repair you're looking at.

regards,

-gb-

Don Palomaki · July 21st, 2005, 04:27 AM

If it is only on playback, and only visible on parts of the image that are changing from frame-to-fram (e.g., moving) it sounds like an uncorrected tape read error. Internal correction is covering the static parts of the image with data from a previous frame.

Is it consistent in terms of which frame and location in the frame is bad from one playback oto the next?

Any differnece between analog and digital output from the XL1?

Can you reproduce the problem on a fresh new tape before and after a head cleaning?

Do known good previously recorded tapes play OK?

Did you try play the problem tape in another system known to be good?

Grady Anderson · July 22nd, 2005, 10:55 PM

Is it consistent in terms of which frame and location in the frame is bad from one playback oto the next?

NO, THE NOISE OCCURS IN SEVERAL DIFFERENT PLACES IN THE FRAME. NO CONSISTANCY.

Any differnece between analog and digital output from the XL1?

NO, ANOLOG AND DIGITAL OUTPUTS PRODUCE SAME NOISE.

Can you reproduce the problem on a fresh new tape before and after a head cleaning?

YES, FRESH TAPE AND FRESH HEAD CLEANING

Do known good previously recorded tapes play OK?

YES, THE PREVIOUSLY RECORDED TAPES LOOK FINE

Did you try play the problem tape in another system known to be good?

YES, THE BAD TAPES DISPLAY THE NOISE ON MY OTHER CAMERA

This is really upsetting.

Chris Hurd · July 22nd, 2005, 11:06 PM

Canon service, right away.

Contact info located at http://www.dvinfo.net/canon/skinny.php#service

Be sure to include a tape which clearly shows the problem.

Dan Vance · July 23rd, 2005, 12:10 AM

This is out of my area of expertise, but hey, I never let a little thing like that stop me! But I was just reading up on compression techniques and this sounds like a problem in the DV compression stream. Those are classic motion compression artifacts. Not that that helps--it's still gotta go back to the factory, but just for future reference/identification, it's probably a bad chip in the codec circuitry or firmware.

Don Palomaki · July 23rd, 2005, 05:04 AM

Thought that with DV, there was no interframe compression, each fame stands alone in the compression scheme. Would motion artifacts as describes appear in this case?

In any case, contacting Canon sounds like the best bet.

Dan Vance · July 23rd, 2005, 01:52 PM

Quote:

Originally Posted by Don Palomaki

Thought that with DV, there was no interframe compression, each fame stands alone in the compression scheme.

That's what I thought too, but as it turns out, the DV compression scheme does look for motion between *fields*. If there's little motion the entire frame is compressed, but if motion is detected the fields are compressed individually.
So from what Grady is describing, it sounds like the codec is not detecting the motion and is compressing everything as if it were a still image.
Sounds like a cool effect though. Wonder how we could do that on purpose...

Grady Anderson · July 25th, 2005, 10:58 PM

Something new....While inspecting me XL1, I noticed a clicking sound coming from the deck when playing a tape. I removed the door and saw the little silver bar with a spring attached (i guess its some sort of mechanism that takes up tape slack or something) and it was bouncing back and forth. The spool for the tape seemed to be jerky when playing, therefore bouncing the "tension bar". The clicking and the playback noise seem to be in sync. *Please forgive my ignorance of technical terms*. Thanks for all your help!

Ash Greyson · August 1st, 2005, 05:16 PM

You may have a head or tape track issue. This happened to one of my XL1 cams. Images recorded in 30P looked fine but 60i at a 1/60th shutter left the mosaic artifacts you explain. I cant remember what they fixed, it has been YEARS but it was $400....

ash =o0

July 20th, 2005, 09:27 AM	#1
Grady Anderson New Boot Join Date: Jul 2005 Posts: 5	XL1 Issue...Strange!!! I'm having an issue with my XL1 which has me baffled. When I am recording from a tripod, or any other stable platform, and there is no motion in the frame, my picture looks great. But, once motion occurs, let's say someone walks into the picture, I am getting mosaic noise on just the part of the frame in which the motion is ocurring. The noise stays with the motion and all stationary objects remain clean. Does anyone know what thats all about? I have searched the web inside out.

July 21st, 2005, 04:27 AM	#6
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,487	If it is only on playback, and only visible on parts of the image that are changing from frame-to-fram (e.g., moving) it sounds like an uncorrected tape read error. Internal correction is covering the static parts of the image with data from a previous frame. Is it consistent in terms of which frame and location in the frame is bad from one playback oto the next? Any differnece between analog and digital output from the XL1? Can you reproduce the problem on a fresh new tape before and after a head cleaning? Do known good previously recorded tapes play OK? Did you try play the problem tape in another system known to be good? __________________ dpalomaki@dspalomaki.com

July 22nd, 2005, 11:06 PM	#8
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Canon service, right away. Contact info located at http://www.dvinfo.net/canon/skinny.php#service Be sure to include a tape which clearly shows the problem. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

July 23rd, 2005, 05:04 AM	#10
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,487	Thought that with DV, there was no interframe compression, each fame stands alone in the compression scheme. Would motion artifacts as describes appear in this case? In any case, contacting Canon sounds like the best bet. __________________ dpalomaki@dspalomaki.com

July 20th, 2005, 09:31 AM	#2
Jimmy McKenzie Major Player Join Date: Jan 2004 Location: Waterloo Ontario Posts: 721	Assuming you are 0 gain, no shutter effect, standard mode not frame mode, and your heads are recently cleaned and the tape is brand new, then likely the heads or the drum are in need of servicing. You've had the camera for 6? years ... has it ever made the trip in for servicing? This sounds like a drum problem. You might want to try a different lens just to rule out the possibility of a lens problem...

July 20th, 2005, 09:45 AM	#3
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	Unless he is seeing this in the v/f live while in pause mode. In which case, the camera has a serious malfunction and needs to be sent in for repair. The viewfinder doesn't show what's recorded to tape when recording. -gb-

July 20th, 2005, 10:40 PM	#4
Grady Anderson New Boot Join Date: Jul 2005 Posts: 5	That is correct, I do not see the noise in the viewfinder, only in playback. 0 gain, no shutter effect, standard mode not frame mode, and my heads are recently cleaned and the tape is brand new. I purchased this camera second hand and I have owned it for about 1 year. I have not sent it in for servicing before. How much does something like that cost?

July 20th, 2005, 10:53 PM	#5
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	Sounds to me like you might have a DSP chip gone bad. Since you don't see this problem in the v/f except during playback, it's tough to figure out just where the bad data is entering the record stream (electronics, or tape transport). Have you by chance tried playing back some of that footage on another mini DV device? That would help narrow it down for the Canon folks if the recorded tape plays fine on another deck or camcorder. Tough break. I don't have any idea what kind of cost to repair you're looking at. regards, -gb-

July 22nd, 2005, 10:55 PM	#7
Grady Anderson New Boot Join Date: Jul 2005 Posts: 5	Is it consistent in terms of which frame and location in the frame is bad from one playback oto the next? NO, THE NOISE OCCURS IN SEVERAL DIFFERENT PLACES IN THE FRAME. NO CONSISTANCY. Any differnece between analog and digital output from the XL1? NO, ANOLOG AND DIGITAL OUTPUTS PRODUCE SAME NOISE. Can you reproduce the problem on a fresh new tape before and after a head cleaning? YES, FRESH TAPE AND FRESH HEAD CLEANING Do known good previously recorded tapes play OK? YES, THE PREVIOUSLY RECORDED TAPES LOOK FINE Did you try play the problem tape in another system known to be good? YES, THE BAD TAPES DISPLAY THE NOISE ON MY OTHER CAMERA This is really upsetting.

July 23rd, 2005, 12:10 AM	#9
Dan Vance Built the VanceCam Join Date: Apr 2004 Location: Prescott Valley, AZ Posts: 109	This is out of my area of expertise, but hey, I never let a little thing like that stop me! But I was just reading up on compression techniques and this sounds like a problem in the DV compression stream. Those are classic motion compression artifacts. Not that that helps--it's still gotta go back to the factory, but just for future reference/identification, it's probably a bad chip in the codec circuitry or firmware.

July 25th, 2005, 10:58 PM	#12
Grady Anderson New Boot Join Date: Jul 2005 Posts: 5	Something new....While inspecting me XL1, I noticed a clicking sound coming from the deck when playing a tape. I removed the door and saw the little silver bar with a spring attached (i guess its some sort of mechanism that takes up tape slack or something) and it was bouncing back and forth. The spool for the tape seemed to be jerky when playing, therefore bouncing the "tension bar". The clicking and the playback noise seem to be in sync. Please forgive my ignorance of technical terms. Thanks for all your help!

August 1st, 2005, 05:16 PM	#13
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	You may have a head or tape track issue. This happened to one of my XL1 cams. Images recorded in 30P looked fine but 60i at a 1/60th shutter left the mosaic artifacts you explain. I cant remember what they fixed, it has been YEARS but it was $400.... ash =o0