Nikon D70: Noise on long exp: bright top left corner

[aculharobed]

And now, for my next trick, I will put the camera in the freezer and see if it really is the heat. Wasn't such a good thing to have it tucked under the blankies, eh?

[Peter_AUS]

Try covering the viewfinder as well, just as a matter of experiment.

I know, others will boohaha about that suggestion, but humour me as well.

[Sebastian]

Heat coming off of the control circuit for the CCD. The higher the sensitivity, the sooner it will creep up. Only happens with CCDs, not CMOS. Freezing the sensor will help, but don't waste your time, it's an accepted and expected quality of CCD sensors. If you can't live with it, get a camera with a CMOS or turn on dark frame subtraction, which will double the time it takes to make the shot, but will remove the artifact.

[aculharobed]

Ok, forget the freezer bit. I don't have much hope of it making a change, anyway. But maybe I'll do it some day when I'm extremely bored.

What is it about CMOS vs. CCD that makes this difference? Does CMOS stay cool, or is it less sensitive to heat, or what?


Flashram_Peter_AUS, the viewfinder was covered. The whole camera was covered.

[peted56]

Has anyone tried this on other CCD based D-SLR's? What was the result? I guess I have to go and try it on mine.

Cheers.

Pete