Hot pixels like wrinkles – over time they get more obvious

[vonRasmussen]

Hi all.

I got my current EOS 1D Mark II N back in May 2006 just before going on a 4 week field trip in Polynesia. I got home with a lot of very nice pictures.
The year after, I did some very cool shots of the Kuala Lumpur skyline by night. But when I got home and processed the raw images in DPP I got horrified – a couple of red dots were to be found on all my night shots.
At that time one of our fellow forum users calmed me down and told about the hot pixels.

Now – with the camera just turning 3 years of age the hot pixel issues has increased quite a bit. More pixels are “hot” – some smaller than others, but still… annoying to have to deal with in the post production.

My questions are:

1. What exactly is causing these hot pixels? Is it the CMOS sensor itself that deteriorates or is it the A/D converser or the DIGIC processor which is mal-processing some areas of the censor data?
   
2. Is there any way to eliminate this issue (at it’s root cause). I assume that replacing the censor (if that’s the cause of the issue) is too expensive…

Kind regards
vonRasmussen

[monobrow]

Re: Hot pixels like wrinkles – over time they get more obvious

It's the image sensor mainly. One of the many thousand miniature connections begins to deteriorate.

You should notice the problem appears to get worse as the ISO settings increase. This is because the amplification circuit the camera is increasing the sensitivity of the signal from the sensor.

It can be repaired by a specialist but may cost a considerable amount of money.

[colin C]

Re: Hot pixels like wrinkles – over time they get more obvious

I understood that the "Repair" was mapping out the hot pixels, unless you go to the expense of sensor replacement.

Colin

[vonRasmussen]

Re: Hot pixels like wrinkles – over time they get more obvious

Hi Monobrow and Colin C

Thanks for your replies.
I was in fact thinking of ways to repair the problem - i.e. replace the part causing the issue. Whereas mapping out the hot pixels is merely a fix of the symptoms.

Of cause mapping the hot pixels will be a easier and less expensive solution. However, I'm not aware if this can be done on Mark II cameras?

Kind regards
vonRasmussen