View Full Version : JVC official white dot explanation


Steve Mullen
September 9th, 2008, 07:43 PM
CCD cameras can develop CCD blemishes where a pixel or two can appear white in the image. These may be caused by atmospheric radiation and also by manufacturing impurities that begin to show after years of use.

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.

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. We DO NOT recommend warming your GY-HD100U in a microwave oven.
__________________
Ken Freed
JVC Mid-Atlantic District Sales Manager
(201) 637-7706
kfreed@jvc.com

Wayne Avanson
September 11th, 2008, 04:02 PM
So we're stuffed then.

Waldemar Winkler
September 11th, 2008, 06:55 PM
kfreed@jvc.com[/email]


So, why don't you take a crack at explaining that good reason. We are trying to use the products you represented as worth owning. We've discovered a problem, and if we are going to really be able to deal with the problem, we need to understand it. We may not all be engineers, but we are not stupid. So, give it a go.

Steve Mullen
September 11th, 2008, 07:20 PM
So we're stuffed then.

As long as pixels go bad over time -- it would seem the only solution is repeat visits to JVC service.

However, knowing that excessive -- burning hot to the touch -- heat may cause this, if one avoids this then it could be years before more go back.

However, he makes it clear that since the process may be needed to be repeated several times -- you may need to send it away several times.

I also wonder about his claims about all non-pro ccd cameras. I've never had a problem with a Sony. So either Sony builds better ccds or ALL their cameras run an auto-mask upon power-up.

Still wonder about a few hour freeze with the power on. If they go bad from heat -- can they heal from cold?

Wayne Avanson
September 18th, 2008, 01:32 AM
Still wonder about a few hour freeze with the power on. If they go bad from heat -- can they heal from cold?

Go on Steve, give it a try…

You know you want to… :-)