Compressed 12-bit vs uncompressed 14-bit shadows on the A7 II

[samueljohnchia]

Hi Guillermo,

Is this test showing regular Sony 13/11 bit lossy compressed raw, or is it 12 bit readout (silent shutter, continuous shot mode, bulb exposure) that you are showing here?

Thanks!

[IliasG]

.. unfortunately the funny Sony firmware 3.0 just allows two options: 'Compressed' (which is 12-bit compressed RAW), and 'Uncompressed' (which is 14-bit uncompressed RAW)...

Hi Guillermo,
Sony's ARW2/3 compressed raws are not 12 bit, (except from Bulb and silent shutter modes) and  it's Dcraw which makes them look like 12bit ..
https://github.com/Beep6581/RawTherapee/issues/1997
https://storage.googleapis.com/google-code-attachments/rawtherapee/issue-2013/comment-4/sony-scaling.patch
(you have to take care of the black level vallue also ..)

In fact at the linear portion (before Sony's curve starts decreasing data density) they are 13bit in 14bit container (half levels missing ).. if you cannot modify/compile Dcraw try by first converting to DNG ..

[Guillermo Luijk]

Hi Guillermo,
Sony's ARW2/3 compressed raws are not 12 bit, (except from Bulb and silent shutter modes) and  it's Dcraw which makes them look like 12bit ..
https://github.com/Beep6581/RawTherapee/issues/1997
https://storage.googleapis.com/google-code-attachments/rawtherapee/issue-2013/comment-4/sony-scaling.patch
(you have to take care of the black level vallue also ..)

In fact at the linear portion (before Sony's curve starts decreasing data density) they are 13bit in 14bit container (half levels missing ).. if you cannot modify/compile Dcraw try by first converting to DNG ..

That's frankly interesting Samuel/Ilias. I was indeed using EFCS in all shots, the Compressed were developed by DCRAW as 12 bit but the Uncompressed as 14 bit. That would explain the unexpected lack of levels in the Compressed shots. The conclusion would be not to use Compressed+EFCS.

However I found another issue on DCRAW 9.27: it doesn't develop properly ISO100 Uncompressed, while the rest of ISOs are OK. Raw Therapee v4.1 has the same problem but v4.1005 fixes the bug. I let Coffin know.



Regards

www.guillermoluijk.com