Dual ISO support
The nice feature has been added to Canon cameras via Magic Lantern software - ability to shoot with 2 isos at the same time, half sensor with the one, and half with the other, significantly increasing the dynamic range.
The page describing dual ISO: http://www.magiclantern.fm/forum/index.php?topic=7139.0
At this time, the workflow requires to convert the .CR2 file to .DNG via the utility "cr2hdr" and then develop with raw convertors, thus wasting a lot of disk space with .DNG files.
I would be eager to help implementing the direct support for dual ISO raw files in Darktable. Just don't know where to start digging.
#2 Updated by Johannes Hanika over 5 years ago
thanks for bringing this up. we're well aware of ML and the awesome things you can do with it :)
of course it's not going to be as simple as calling system("cr2hdr"), but we want more thorough integration of dualiso in dt.
if you're interested, take a look at this pull request:
which needs integration before we can go on with this (cr2hdr requires the black borders around the actual image data and requires that no black level compensation had taken place before).
dual iso itself will need to work on regions of interest for efficiency, i.e. don't interpolate the whole buffer all the time but only what's going to be visible on screen. we also have the design goal that no module should take more than 100ms to run, to avoid unacceptable gui delays. so just calling an external program to process the whole buffer is prohibitive.