The Dreaded Dead Pixel

[Antony Michael Wilson]

I appreciate that dead pixels can happen to all CCDs on any video camera and that it is just a limitation of the technology and that there are things one can do to avoid it. I also appreciate that it is an easy fix on the HD100 (as long as you never need to use gain). However, I'd have to agree that dead pixels do seem to happen with great frequency and regularity on this camera, from what I can tell from this board. I've already had two dead pixels on the HD100 and never had any on any other camera I have ever owned or rented in the last 10 years. Maybe I've just been lucky...

All in all, I think it might actually be a fair criticism of an otherwise great camera.

[Scott Jaco]

Originally Posted by Antony Michael Wilson

I also appreciate that it is an easy fix on the HD100 (as long as you never need to use gain).

Actually I've cranked the gain to +18db without seeing the bad pixel. I think what they are saying is that the bad pixel has to be visable at 0db in order for the software to "mask" it. Once the pixel is masked, it shouldn't be visable at any gain setting, since it's been disabled. At least thats what it would seem.

I have a consumer JVC with a couple of bad pixels also. It's a high-end consumer handycam but it doesn't have the "mask" feature.

I do think you are right, I never see anyone complain about the Sony Z1u's having bad pixels.

[Antony Michael Wilson]

That's interesting. I masked our bad pixel in the well-known fashion and it is always visible again with any gain added. Maybe I have a lemon?

[John Vincent]

It could be another pixel that was next to the original dead one. Try the procedure one more time after the camera is heated up. If it remains, I'd ship it in for inspection/repair, with a list of all the procedures you've tried up to now. Obviously, you can't use the camera w/ a dead pixel...

john
evilgeniusentertainment.com

[Antony Michael Wilson]

I've tried the procedure several times. It's masked fine without gain but the gain brings it back. I was sure that this is normal and I seem to remember Carl Hicks saying that this was the case. Either way, I'm not that bothered because I use gain very rarely...

Carl, if you're reading this, what is the official line on masked pixels with gain up?

[Bill Edmunds]

Originally Posted by Ken Freed JVC

1. The process only conceals blemishes that show at 0db of gain. Blemishes that only show at 3dB, 6dB, 9dB or 18dB will not be corrected. Also there is a threshold that the blemish must be above to be detected. Over time those blemishes may become greater and then show at 0db and then will conceal.
2. Because of a good reason that would take too long to explain, the process can “miss” a blemish. It is absolutely likely that you might have to run the procedure a few times to find the blemish and conceal it.
3. Warming the camera makes the blemishes brighter and easier to correct. Some people wrap the camera in a blanket or coat to help warm it up. We DO NOT recommend warming your GY-HD100U in a microwave oven.

If there is a blemish that cannot be fixed with this solution, what are we supposed to do? Send it back to JVC? What solutions are there for blemishes that show up under gain settings of 6db and over?

[Scott Jaco]

Well, have you tried the "mask" function yet?

[John Mitchell]

Originally Posted by Tim Dashwood

BTW, Atmospheric radiation can cause it, but I think the x-rays at airports are also to blame. I seem to get a new one everytime one of my cameras travels.

Not sure about the X-rays but someone told me that travelling in a jet you are exposed to far higher levels of gamma radiation than standard which could also explain the dead pixels...

[Richard Hunter]

Originally Posted by John Mitchell

Not sure about the X-rays but someone told me that travelling in a jet you are exposed to far higher levels of gamma radiation than standard which could also explain the dead pixels...

Hi John. It's usually cosmic rays that cause problems at high altitudes. Alpha particles can penetrate aircraft skin and equipment housings and take out individual logic gates in memory circuits or CCD cells in cameras. If the damage is temorary (soft error) it is called Single Event Upset, if it's permanent (hard error) then it's Single Event Burnout.

Xrays and gamma rays are not as localised. If they were powerful enough to damage the CCD, they would be more likely to wipe the whole sensor rather than just kill single pixels.

[Marc Brewer]

Helo all,

I've tried "the procedure" but the cursor skips over the pixel masking funtion strait to page back. I can see the pixel in 0 db but of course it shows more in 3 db gain to 6 and above...

ideas anyone?

MB

[Antony Michael Wilson]

You need to be in 24p HDV mode for the pixel mask function to work. Have you checked this?

[Carl Hicks]

Originally Posted by Bill Edmunds

If there is a blemish that cannot be fixed with this solution, what are we supposed to do? Send it back to JVC? What solutions are there for blemishes that show up under gain settings of 6db and over?

Bill,

Have you discussed this with your reseller and / or JVC District Sales Manager?

Carl

[Miko Kirchoff]

I found I had the so called,"DEAD PIXELS" in my brand new JVCGYHD100U and believe me, wasn't too thrilled about it. The insult to my injury was the Express Video Supply Guys not giving me much compassion after spending lots of dough with them over the years. I won't purchase from them anymore. No service after the sale.

Meanwhile, I shot a local car commercial with new camera and when I went to post, found this crazy little white dot on the monitor. I called JVC and after a long, circuitous trip thru an endless maze of recorded message prompts, got a guy in Jersey who showed me the super secret menu allowing the camera to mask out the problem pixels. It worked, or so I thought, 'til I shot a lovely lady against a green screen background on a high res monitor. The dot came back and almost ruined the shoot. I had to frame her in such a way as to avoid having it dance across her face when she moved. Good thing it was Green Screen project or I would have been in some sh**!

I went back to the JVC expert and tried the masking process again. So far, it's been working. I wrote down everything the Tech said step by step (just in case) in my owners manual. If you'd like the info, I'll relay it via e-mail to you.

Meanwhile, I've had this rig over 4 months now and have been shooting with it almost daily, and really don't think much of it.

Miko Kirchoff
skyrocketvideo@yahoo.com

[Mark Silva]

I'd like to ask, out of curiosity, Carl, how many times can the masking function be run before it won't work any longer for masking pixels?

I've heard it can only be done a certain number of times before the masking buffer fills and is unable to function.

[William Hohauser]

Originally Posted by Ken Freed JVC

On the GY-HV100U camera this process is provided in a Service Menu accessed while in 24p mode by holding the Focus Assist button (the one on the camera body) when you press and hold the Menu/Status button for at least 5 seconds. You must be in 24p mode for this operation.

You see an advanced menu where the second line says CAMERA1. Move the cursor down and push the shutter wheel to enter that menu and now you have a list with the sixth item being PIXEL COMPEN. Move down to it and select that item, the word CANCEL blinks. Change it to EXECUTE and push again. It takes about 10 seconds or so to perform the operation and then tells you to power off the camera. You are done. Make sure Focus Assist is now OFF and exit 24p mode if desired.

I am unable to get the advanced menu at all. The camera is in 24p mode, no tape and on AC power. It has the firmware upgrade from JVC.

Are the buttons pressed simultaneously or in succesion? If in succession, is the Focus Assist button first or the Menu button? When does the 5 seconds start?

Any help would be appreciated, a dreaded dead pixel has appeared.