View Full Version : Masked Dead Pixels Show as Black Specs
David Parks January 11th, 2007, 04:57 PM So, I just got my HD 100 back from JVC for warranty maintenance. I mentioned to them (through my dealer) in writing that I needed some dead pixels looked at. It looks like they ran the pixel masking routine to try to smooth them out. Only now when I see the uncompressed component output on my monitor I see about 15 or so black specs. I know that they're pixels because they flicker and are square. (Not dirt) Plus I can even see them without the lense attached.
So next, I ran the operation myself, about 8 times total and the specs are still there.
I've ran several 720/24 workflow tests to see if I could see the BLACK PIXELS when compressed into m2t, m2v, QT DNXHD 90 and DNXHD110 HDV, along with some tests in DV24p. The pixels due seem to get fainter with compression and I don't know if the average person would even notice once it goes to air or DVD. You can see them pretty good in m2v.
But, they are there . My question is that is this something I need to accept as a limitation of CCD technology or is this a problem that I need JVC to fix.
My camera is under warranty for 3 more weeks.
Thanks.
Mark Silva January 11th, 2007, 05:44 PM I wonder if somehow the masking is not matching up with your black level values or gamma.
David Parks January 11th, 2007, 06:01 PM I wonder if somehow the masking is not matching up with your black level values or gamma.
Interesting theory.
If so do you think this is a calibration issue (JVC), firm ware, or user setting?
Tim Dashwood January 11th, 2007, 07:48 PM David, could you please attach an exported TIFF or small m2t from one of your captures?
The pixel compensation system in the HD100 is supposed to clone or average the value of the pixels around it, not just make it black.
I wonder if your monitor might have some burnt out pixels?
Stephen L. Noe January 11th, 2007, 09:12 PM So, I just got my HD 100 back from JVC for warranty maintenance. I mentioned to them (through my dealer) in writing that I needed some dead pixels looked at. It looks like they ran the pixel masking routine to try to smooth them out. Only now when I see the uncompressed component output on my monitor I see about 15 or so black specs. I know that they're pixels because they flicker and are square. (Not dirt) Plus I can even see them without the lense attached.
So next, I ran the operation myself, about 8 times total and the specs are still there.
I've ran several 720/24 workflow tests to see if I could see the BLACK PIXELS when compressed into m2t, m2v, QT DNXHD 90 and DNXHD110 HDV, along with some tests in DV24p. The pixels due seem to get fainter with compression and I don't know if the average person would even notice once it goes to air or DVD. You can see them pretty good in m2v.
But, they are there . My question is that is this something I need to accept as a limitation of CCD technology or is this a problem that I need JVC to fix.
My camera is under warranty for 3 more weeks.
Thanks.
I'd turn the camera right around and send it back in immediately.
David Parks January 11th, 2007, 09:24 PM Here's 4 tiff's from the original m2t. I purposely used out of focus shots so you can see that it is not part of the environment. Sorry I had to winzip because of site file limitations.
David Parks January 11th, 2007, 09:30 PM Here are some shots exported out of Liquid (m2v) to tif.
David Parks January 11th, 2007, 09:34 PM 2 more tif from m2v.
David Parks January 11th, 2007, 09:39 PM Tim or Stephen, If you get a chance, I hope you can glance at these. I know for a fact that it is not my monitor, and some of these pixels appeared as white dead pixels before. They seem to stand out against a solid background the most, like the blinds in the shot. By the way, these were viewed on a 1400x900 pixel 19inch Westinghouse, straight out of the camera, and within Avid Liquid full screen.
Thanks, Greatly appreciated.
ps, If these aren't funky pixels then I need to go to the eye doctor.
Stephen L. Noe January 12th, 2007, 06:41 AM The only suggestion I could make to the issue is to try and run the pixel mask routine yourself and see if it's any better. If it's not then send the camera back in. Your images show ALOT of specks all over the place.
Another thing to try is to put your camera's shutter speed to a low number. Do you have specks all over the screen? Put your lens cap on, do you have specks all over the scene?
Jiri Bakala January 12th, 2007, 08:02 AM Any chance that it's dust on the sensor?
David Parks January 12th, 2007, 09:26 AM Thanks, Stephen for looking at the tiff's. I lowered the shutter to 1/6th and man, tons of white pixels show up. It looks like a hail storm. With and without the lens and lens cap.
I'm a little worried that JVC won't do anything, my dealer knows nothing about this camera and they're not authorized to even touch it.
Since this has already been to JVC once is there someone within JVC that could look at this?
Not much time left on the warranty.
Thanks.
Tim Dashwood January 13th, 2007, 10:50 AM David,
It looks like Carl Hicks is your district rep, but he hasn't posted here since Monday so he's probably busy at CES and hasn't read this thread.
Here's his contact info as posted on the JVC Site.
http://pro.jvc.com/prof/attributes/dealerlookup.jsp?code=D&feature_id=00&itempath=null&tree=null&model_id=MDL101539&zipcode=77001
If you can't reach Carl on Monday, try calling 1-800-582-5825 tech support and find out what your next step should be.
David Parks January 13th, 2007, 01:23 PM Thanks Tim, much appreciated.
Cheers.
Terry Nixon January 13th, 2007, 03:05 PM CES is for consumer products.
you can probably reach Carl Hicks on Monday. He's pretty good and making himself available.
You can also contact the JVC sales engineer, Rob Yaroush, listed on the previous link and discuss your situation.
Carl Hicks January 15th, 2007, 12:25 AM CES is for consumer products.
you can probably reach Carl Hicks on Monday. He's pretty good and making himself available.
You can also contact the JVC sales engineer, Rob Yaroush, listed on the previous link and discuss your situation.
Here I am, and as Terry is correct, I do not attend CES.
David, please e-mail me your phone # and the name of the dealer you purchased from, and I'll give you a call.
Regards,
Skye Fitzgerald January 19th, 2007, 01:28 PM David,
Sorry to enter this conversation so late...
I am having a similar problem with my JVC 100. A couple prominent, dead pixels developed very rapidly during the course of a recent shoot for CNN. I used the pixel compensation feature in an attempt to address the issue in the field. Interestingly enough, after three runs of the program it masked the highly noticable dead pixels...however, only a week later during the course of a single, hour-long interview another area developed a similar problem! So I am now faced with running the pixel comp. application yet again in the hope that my next shoot won't be ruined (and the next, and the next...)!
In my case, these areas are large enough to either render the footage unusable, or to force an editor to mask them manually in post afterwards. Because I shoot for broadcasters such as CNN and Dateline, it's a dangerous proposition to risk an entire shoot due to a faulty unit. I have never had this problem with other camera manufacturers and don't believe it falls within the range of acceptable pixel loss. The camera is only six months old.
I hope you sent your camera back to JVC and get some satisfaction.
-Skye
David Parks January 19th, 2007, 09:56 PM Skye,
You might have that looked at, especially if your camera is still under warranty. But, I understand you can run the pixel mask compensation up to like 100 times before the memory buffer overloads. So you might try it again. In my case I have run the pixel mask routine about 15 times. However, in my case several of the pixels didn't average correctly during masking with other pixels around them and showed up as black specs. In all, I had about 17 or more black specs and the masking didn't fix the problem. I think if they had averaged properly then it wouldn't have been an issue.
Carl Hicks and JVC have been very helpful and the camera was shipped off to service a couple of days ago.
I'll let you know what happens when I get my camera back.
David Parks February 20th, 2007, 08:27 PM Sometimes we forget that bad things can happen to good cameras.
Got my camera HD 100 back about 2 weeks ago. Just in time for 2 shoots.
And the camera is making gorgeous pictures. I want to thank JVC's Carl Hicks (who I actually got to meet here at a product show along with Robert Yarosh, a JVC sales engineer) for making sure that my camera was taken care of. And whoever the tech was at JVC, well he did a great job. I couldn't find one blemish, anywhere. So, guys when you have a maintenance issue (or issues), you can be confident that JVC will back these cameras.
And oh by the way, I met Chris Hurd at the show as well, making the rounds. Nice guy. He was standing right behind me when I was talking about all the info I get from DVINFO.net. Weird conicidence.
Oh and I want to thank Stephen Noe for taking the time to actually make circles around all of pixels in question on the TIFF files. That was very nice. I owe you one.
John Vincent February 22nd, 2007, 11:01 AM That ends well, huh? I'm glad your camera got repaired and that Carl and the boys over at JVC rsponded in such a positive manner.
This kind of professionalism is exactly the kind of thing that will build loyality. You had a great point in saying that even a good camera can go bad.
And Stephen is the man, no doubts there...
Thanks for letting us know how it all worked out -
john
evilgeniusentertainment.com
John Damberger March 12th, 2007, 12:49 PM Cleaning tape 5x, works great in SD, only HD do I get horz fine gray lines randomly. while recording does not show it, only during play back. It records to the tape because shows on other JVC cam.
Anybody else have this issue? its off to Cypress right now
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