CinemaDNG Raw compatibility?

(Greg W) #1

Forgive my ignorance if I am way off base here, but I came across this software in my search for a way to correct fixed pattern noise (dark frame subtraction) in the CinemaDNG Raw files from my Blackmagic URSA. After installing RawTherapee and navigating to the location of my DNG’s it was quickly apparent they could not be read. I browsed the documentation and found some details about adding compatibility but the manual method is a bit beyond my technical expertise, so I thought I would post in the hopes that someone could advise me as to whether this is even possible or if this software is strictly for the Raw files that come from still image cameras.

(Mica) #2

I can’t say whether it’ll work or not, but posting a sample dng file here (or uploading it on would be helpful. Even better of you can release your file under the creative commons zero license so whoever needs the file can use it :slight_smile:

(Greg W) #3

Thanks for the heads up, as soon as I get back to my gear tomorrow I’ll see about posting one of the DNG’s.

(Greg W) #4

Here is one of the DNG’s from my Blackmagic URSA, as requested. Please let me know any other details you might need. Thanks!

Blackmagic URSA_1_1999-12-31_2153_C0003_000001.dng (8.7 MB)

(Morgan Hardwood) #5

Confirmed that this file is not decoded correctly in RT5.
Issue opened:
I won’t have time to investigate in the next few days.
@wnterbass can we keep this file and copy it to our server?

(Greg W) #6

Yes, you may keep the file and use it in any way you wish, and add it to your servers for anyone who may wish to use the file for investigation. Thanks so much.


Could you please upload it to for future reference? I could do it, but formally releasing it as CC0 can only be done by the author. :slight_smile:

(Greg W) #8

Uploaded to the repository. If anyone needs any further details please feel free to ask.

(Morgan Hardwood) #9

@wnterbass please see
Can you confirm that this DNG file came directly from your camera and that you downloaded it directly off the memory card without using any special downloading software? Some downloading software is known to edit (read: corrupt) files. If you did, can you supply a new one, directly from the camera, transferred by traditionally copying it using My Computer or whatever in Linux and macOS?


Just in case, LightZone can open the file, although not having, as expected, the raw tone curve for it. LZ is using a modified dcraw (v9.27 (1.477)) in the last version.

(Greg W) #11

I can confirm that the file was copied directly from the camera’s drive and not altered or edited in any way. After reading the thread on github I can also confirm that the files contain 16 bit information compressed to 12 bit in the file, then read back out to 16 bit when I edit them in the software (Davinci Resolve).

(DSDT4k) #12

I’ve stumbled into this discussion via Google - I as well attempted to open a URSA 4K uncompressed DNG using Raw Therapee 5.3 on OSX 10.9 and got an identical result to your screenshot. - I checked Git comments and the issue is open - As far as I know only the 4K URSA camera files open as a magenta pattern, the 4.6K URSA files open fine. I happen to have the former and not the latter camera. Let me know if you need any more CDNG sample files.