Showing results for 
Show  only  | Search instead for 
Did you mean: 

EOS 1D X Mark III - C-RAW decompression software


Hi! My new 1DX iii was accidentally set to C-RAW instead of RAW, and I'm bummed, because I've always shot at highest quality RAW. I've read that software can decompress C-RAW images but I cannot find any such software online. Might anyone be able to offer a recommendation?

(I mostly download, process, etc. using Capture One, or occasionally ADOBE CS. All are up to date.)

Thank you.



Canons free Digital Photo Pro 4 (DPP4) will open them and allow an export to PhotoShop, but it's my understanding that cRaw uses lossy compression, so some of your data is gone regardless of what program you use to decompress.

Some folks don't notice much difference, or at least that's what they report. But, like you, I prefer all the data I can get and have never compared the two formats. I once accidently shot a whole day in JPeG, and boy was I bummed.


EOS R5, R6, R6II. RF 15-35 f/2.8L, 50mm f/1.2L, 85mm f/1.2L, 100mm f/2.8L Macro, 100-400mm, 100-500mm L, 1.4X.

Thank you! I'm looking at them in Capture One. I might compare PS or Adobe Camera Raw.


Any software using Libraw should be able.

Latest Adobe Camera Raw and Lightroom should also be able to open C-RAW.

The quality loss you get is in the deep shadows. Here the optical black area brightened. Your software normally crop out this. I think this was brightened 4-5 stops.




Thank you! Very helpful. I run a comparison across PS, Adobe Camera Raw, and Capture One. Thus far, they seem OK, but I'm glad I discovered the "error." It's better than shooting JPEG, so at least that didn't happen.

The 1DX III is an incredible body but you really do have to go through all of the setup out of the box (or if you are using a pair of them, copy settings over from the other body) because the defaults probably aren't right for your use.

I picked up a second 1DX III and put one of my 1DX II bodies into semi-retirement last week and did my usual 1DX series setup.  But somewhere between my early production 1DX III and the new production, the default for lock control settings left the shutter speed unlocked locking only aperture.  I was shooting a track meet with the new body and shot part of a new school record pole vault @1/8000 instead of my initially selected 1/2500 which was my chosen setting.  It is easy to bump a control when shooting an event with 3 bodies and lenses.

Fortunately it was bright sunlight and didn't matter because the ISO remained in the virtually no noise range but I quickly added shutter speed to the locked controls to keep that from happening again.

One of the very useful and often overlooked features on the 1DX bodies is the ability to instantly shift between two sets of exposure settings with the mfn button.  I always shoot sports in manual mode with auto ISO and I store a second set of settings for group/post score celebration shots in C1 with reduced shutter speed and narrow aperture for increased depth of field at low ISO.  A tap of the button allows you to instantly cycle between these two settings.

You just have to make sure to keep an eye on the viewfinder info so that you don't forget and stay in the wrong setup.  Even better would be having the mfn button set up as a hold to temporarily change rather than a toggle between settings.


EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video