View Full Version : Dead pixels and split screen


Bill Edmunds
September 10th, 2006, 05:53 AM
In reviewing fotage from my HD100 (all of 2 months old), I have noticed two dead pixels near the center of the screen. This tends to show up when the camera has been operating for a few hours. Also, I can see the split screen effect slightly in low light situations. The latter isn't really much of an issue, but the dead pixels are. Assuming I send this back to JVC, how quickly will it be repaired and will it likely occur again?

Scott Jaco
September 10th, 2006, 08:31 AM
There is a thread that explains how to perform the pixel mask function which should fix the dead pixels.

As for the SSE, it's just somthing HD100's do. If you are seeing the SSE under "normal" lighting/shooting conditions, then send it in for calibration.

If you are shooting a dark room with no camera light, don't expect much sympathy from JVC.

JVC won't fix it unless it is visable under normal conditions.

Bill Edmunds
September 10th, 2006, 08:33 AM
There is a thread that explains how to perform the pixel mask function which should fix the dead pixels.
Thanks!

As for the SSE, it's just somthing HD100's do. If you are seeing the SSE under "normal" lighting/shooting conditions, then send it in for calibration.

If you are shooting a dark room with no camera light, don't expect much sympathy from JVC.

JVC won't fix it unless it is visable under normal conditions.
Nah. The SSE is very minor and doesn't bother me.

Scott Jaco
September 10th, 2006, 08:35 AM
Here is a quote from that thread, it will explain everything. This is from a JVC rep.

"This is so common on CCD cameras by all manufacturers that we all build into our pro cameras the ability to detect and correct these blemishes.

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.

However there are a few things for you to note about this process:
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."

Bill Edmunds
September 10th, 2006, 08:38 AM
Here is a quote from that thread, it will explain everything. This is from a JVC rep.

"This is so common on CCD cameras by all manufacturers that we all build into our pro cameras the ability to detect and correct these blemishes.

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.

However there are a few things for you to note about this process:
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."
That's very helpful. It's disappointing that it only works at 0db. This post also makes it sound like you should expect dead pixels with the camera. Never had this issue before with any camera, quite frankly. So does this mean it's not something that JVC will fix?

Scott Jaco
September 10th, 2006, 11:45 AM
It masks pixels that appear at 0db, once the pixel is detected, it shouldn't show up at any gain level since it's been removed. I've removed pixels then cranked it up to 18db without seeing it.

JVC just has a weakness with getting bad pixels. It's no secret, just be glad they have a way to cure it.

Mark Silva
September 11th, 2006, 10:16 AM
I've seen plenty of Canon GL1's / XL1's and Sony' camcorders with hot pixels.

What I've heard more than once is that these companies use "rejected" chip yields from what would have been used in professional camera's.

These ccd's that don't meet the tough standards have a tendency to fail and thus become hot.

Scott Jaco
September 11th, 2006, 10:49 PM
I've seen plenty of Canon GL1's / XL1's and Sony' camcorders with hot pixels.

What I've heard more than once is that these companies use "rejected" chip yields from what would have been used in professional camera's.

These ccd's that don't meet the tough standards have a tendency to fail and thus become hot.

Wow! But isn't the HD-100 a unique CCD? Isn't it the first JVC camera to have the 1280x720 3-chip CCD?

Richard Hunter
September 11th, 2006, 11:15 PM
Wow! But isn't the HD-100 a unique CCD? Isn't it the first JVC camera to have the 1280x720 3-chip CCD?

It's actually 2 CCDs, that's why the split screen problem exists.

Richard

Steven Thomas
September 12th, 2006, 06:53 AM
Actually,
The HD100 has 3 CCDs.

According to their documentation on their web site, they use a process called
HSTR (High Speed Twin Readout). This process simultaneously reads the right and left portion of image.

See:
http://pro.jvc.com/prof/attributes/faq.jsp?model_id=MDL101539&feature_id=13#chips

Bill Edmunds
September 12th, 2006, 08:25 AM
What I've heard more than once is that these companies use "rejected" chip yields from what would have been used in professional camera's.
But these are 1/3" chips. Professional cameras use either 1/2" or 2/3" chips.

Mark Silva
September 12th, 2006, 10:01 AM
They all originate from silicon wafers.

I'm not claiming that JVC utilizes rejected materials for the ccd imagers on the HD100-U.

But they were definitely in the GL1 / XL1 / VX series cameras.

It's one way to get a pretty darn good image but keeping that part of the cost down.

I had hot pixel issues Twice on a brand new GL1, the first happened literally days out of the factory warranty. I should have sold it, but I had it repaired for $ 1,000 and then again it had hot pixels. I won't ever own another canon product for that.

Scott Jaco
September 12th, 2006, 11:59 AM
Thats terrible. Be glad that JVC has a quick fix, since it seems most mid-range cameras don't.

Mark Silva
September 12th, 2006, 01:57 PM
I am.

I was so happy to hear they had the pixel masking as an option.

Richard Hunter
September 12th, 2006, 06:55 PM
Actually,
The HD100 has 3 CCDs.

According to their documentation on their web site, they use a process called
HSTR (High Speed Twin Readout). This process simultaneously reads the right and left portion of image.


Hi Steven. I thought I read somewhere that there were 2 CCDs (per colour channel) butted together to give the HD resolution, and that this was the reason for the SSE. Sorry for spreading untrue "facts" and thanks for the clarification.

Richard

Jonathan Nelson
September 12th, 2006, 07:05 PM
Hi Steven. I thought I read somewhere that there were 2 CCDs (per colour channel) butted together to give the HD resolution, and that this was the reason for the SSE. Sorry for spreading untrue "facts" and thanks for the clarification.

Richard

From what I have gathered, each half of each ccd uses a seperate processor to reduce heat and save power.