Thank you very much for your help! I did some more "testing" today and set the exposure time to 5 seconds so I would basically get a white picture and calculated the maximum of each channel. This is what I got:
ISO R G B
400 15760 15761 15761
500 15760 15761 15761
640 12810 12811 12811
800 15760 15761 15761
1000 15760 15762 15760
1250 12810 12813 12810
1600 15764 15767 15763
Now at least I know what value I have to normalize with. I still have one technical question: Why are the values for 640 and 1250 different than the others?
Thank you very much for your help! I did some more "testing" today and set the exposure time to 5 seconds so I would basically get a white picture and calculated the maximum of each channel. This is what I got:
ISO R G B
400 15760 15761 15761
500 15760 15761 15761
640 12810 12811 12811
800 15760 15761 15761
1000 15760 15762 15760
1250 12810 12813 12810
1600 15764 15767 15763
Now at least I know what value I have to normalize with. I still have one technical question: Why are the values for 640 and 1250 different than the others?
bye, Peter