Thanks for the link Bill. The bottom graph is easy enough to understand, but the top one is a complete mystery to me.


for what it's worth, I've never seen any combing in my RAW files.


I worked my way through the links and found his 40D page, with the same "dark noise tests he did for the 30D. But I still can't make sense of it.


He refers to the 'tween ISOs as "upscaled fake ISOs" and "downscaled fake ISOs." The only conclusion I can draw (so far, without some help) is that the sensor multiplies or divides the native ISOs to arrive at the 'tween ISOs.


But he never says if that's a bad thing (though the word "fake" doesn't exactly inspire confidence in using them!).