"must have"...
Anyhow, it all depends just what it is you tested and how you tested it. What does 'clipped both ends' mean? Were you analysing the raw file or working with a raw processor, if so which one? How did you set the black and white levels? And so on.
The figures I gave don't say what is usable, they just show the extent of information content. What you consider usable and how you use it is up to you.
8 months ago
78
question Bob, i set DRO on my a7iv today at 5 which is its highest setting and the noise from lifted 5 stop underexposure had less noise (.5 stop) than DRO set to 1, is the camera just manipulating the raw file in camera to achieve the better result. ?
i used the camera first set to zebra 109 +1 which is very close to the raw file,then confirmed the results in ACR. was only a quick and dirty experiment. next time i will try to shoot a 12 stop scene. to over cast today for proper test. as you need veiling glare to raise its head 😁
I'd never use a DRO setting if working with raw. DRO is about OOC JPEGs really. Generally they set up the sensor to reduce read noise (I'd guess that Sony would switch in the higher conversion gain) and expose brighter than they would normally for that setting. The high conversion gain would track with what you found.
ACR's doing a lot there. To really find out what the camera's doing in terms of potential tonal range you need to do a linear raw conversion (for instance, with dcraw or one of its successors) and two different lightness adjustments to find out where at the top and bottom ends you can differentiate tones. You can't do it with one because the camera will almost always give more tonal range than the viewing device you're using.
Exactly right. The noise dithers. Just like your printer can only print black and white (if you've got a cheap one) but can still produce a range of greys.
all the latest cars are very small, with the exception of those that are not....