It's not what I said and doesn't have anything to do with what I said. The sensor may be linear but the S-slope is not and nor is the sensors outcome, the input is not imported linearly to the sensor either. In fact to produce the S-slope the sensels are controlled at different Iso value depending on the light intensity they receive. This means that depending on the shot, the sensor directs some pixels to higher, some others to even higher, some others to different, some more to lower (etc)... sensitivity to achieve the S-slope. Thats not very linear behavior is it? That is exactly why you see noise at the deep shadows, even if you set sensitivity to the minimum. In fact the logic (control circuit) of the sensor is trying to fool the sensor and make it behave like film, its just that they haven't succeed yet, but its getting better all the time..., lets hope this time they will succeed! Merry Christmas, Theodoros. www.fotometria.gr
The outcome of the sensor is a raw file that, at least at base ISO, does not contain any S curve. The S curve is applied when converting the raw file.
I guess that the point you are trying to make may be:
- Some sensors apply some form of amplification of the electric signal at higher ISOs, and this amplification may not be applied linearly. I would be interested in factual data you might have about this?
- Not all sensors have the same quality of analog to digital conversion near saturation, which may result in harsher transitions from non blown to blown areas. In essence, this would mean that some sensors behave non linearly near saturation. This may be true accross a very small range of illuminations, but would still basically not explain the highlight DR you claim exists.
Sorry, I still don't see anything in your argument that would explain highlight DR. Until proven otherwise, I'll stick tot the well accepted proposal that DR with linear sensors is ONLY depednant on shadow noise. The rest is just a pleasant illusion.
Merry x-Mas to you as well!
Cheers,
Bernard