It's interesting that this demo clearly shows up the banding which made me declare that back as defective
I am not convinced, that it is really defective, and I am not convinced, that you should not use it with higher ISO (your dealer does not know the camera).
If you are interested on it, the post (yousendit) pls following shots (raw files, of course):
1. whatever, with the lowest ISO, metered for that ISO,
2. shots for all other ISOs with the very same exposure
, i.e. successively overexposing,
3. one shot with the banding, the raw file and a crop showing the banding in the converted TIFF or high quality JPEG.
As far as Sinar know, ISO is just a postprocessing setting in all the current backs including their own, which makes defining exactly what underexposed means a topic of debate
Well, I could say "underexposure" means, that you have to adjust the intensity in raw processing so much, that the banding becomes visible.
However, I used the term differently. I admit it is not correct, and I don't want to redefine "underexposure", but there is no short term for this: the distance in EV measured from the very right
In other words, my "underexposed by almost four stops" means, that the exposure could have been increased by almost four stops without causing relevant pixel clipping on raw level.