Hi every experts!
I bought a second-hand 1Ds mark iii, which was manufactured in 2008.
Yesterday, I tested it for dead pixels, to find out that it has a lot of dead/hot pixels. The shutter speed is 30s, ISO 200, with body cap on and viewfinder closed. There are 101 dead pixels, and 924 hot pixels.
The situation will be worse when increase the iso number.
I have used the "clean sensor manually" hoursly. But still few luck.