I´m looking for a way to match the sensor of my Sony A1 Photo Camera with the sensor of the Arri Alexa Mini Film Camera. You might ask why I would want to do that…
I´m working on a Movie that consist of both Photo and Videomaterial. The Editing and Color Grading will be done in Davinci Resolve, and therefore I need to bring the Photos into that timeline.
To perfectly match the material I shot Color Targets with both cameras. The Videocamera doesn’t shoot in RAW and uses a Logarithmic Profile in order to maintain as much Dynamic Range as possible.
Straight out of camera the material looks very flat and desaturated.
My idea would be to create a profile for the Sony A1 which matches the Arri Alexa Sensor in Adobe Camera RAW. Therefore i would need to create a Matrix in linear space the matches the A1 to the Arri Alexa. Once applied I could export 16bit Tiffs to Resolve and the material from both Cameras would be matched and could be treated in the same timeline. My question is now if that I something I could do with RawTherapee, and if so how would it work. Is there an option to load a Tiff from the Arri Alexa as a reference and match the A1 RAW to it?
I would suggest using Darktable to convert your RAW files to EXR linear/rec2020 files.
These files can be imported in Resolve and converted to ArriLogC3/ArriWideGamut3 (or anything else) using Resolve’s Colorspace Converter node in the color page.
To export ‘real’ linear files, you must disable Filmic and Sigmoid (or any ‘tonemapping’ steps) in your Darktable filter stack.
You can choose linear/rec2020 in the export settings.
Thank you for your suggestion, as far as i understand the conversion doesn´t happen in linear space which would be something i need. Correct me if i´m wrong!
Are you making Exposure / Highlight / Shadow / White Balance adjustments in Darktable before converting into Rec2020 or after the CST Node in Resolve?
How would you compare your method against converting the ARW file to an DNG file (with Adobe DNG Converter) and converting the DNG in the Resolve CameraDNG RAW Tab with these settings:
If the plan is to edit the images and videos with possibly the same settings then I would try to match the images imported into Resolve to the unedited video footage. Since the video camera delivers JPGs with WB, exposure etc all set, matching them would be the responsibility of darktable, imo.
@grubernd
I tired to adjust Highlights and Shadows in Darktable but it seems that this creates a non standard gamma which isn’t supported by Resolve i guess. At least the results are not consistent.
@Xavier_Bourque
I also compared the DNG P3D60 Workflow against your EXR Rec2020 and the EXR seems to work better with saturated Highlights. I lowered the exposure of an overexposed Color Checker (DNG with Exposure in the RAW Tab and EXR with the Master Gain Wheel before CST to LogC) and I increased the exposure of an underexposed color checker. While the underexposed Color Checker comes out similar (little more green tint on the DNG), the overexposed Color Checker keeps the Colours better in place with the EXR Workflow. The biggest difference would be the Magenta Patch I guess.
This seems like a good solution for the biggest part of my problem so thank you very much!
I´m still interested in creating a Lightroom Profile that includes a Linear Matrix which matches the Sony the Alexa. That way i could already “simulate” the Look of the Alexa in Preproduction of a Movie. I tried it with Lumariver Profile Designer but unfortunately it doesn´t allow to match one camera to another…
Is there not a matching feature in DR and a grab the color grade feature also to make a lut… Ibn any case I thought you can just select any image and grab the color grade… or more precisely if you have your color checker shot you could just make a profile to move your inputs from both sources to a common output perhaps one that you might also have grading luts for…
Bit old this link and I dont’ use DR that much but should be doable…
Yes there is. You can just create a CST to linear space and then a Matrix with the RGB Mixer manually which is what i did. And that in combination with the EXR workflow Xavier suggested is for now also the best way to match Sony photos with Alexa Material.
But ideally i would find a way to convert the Sony Files with a costum Profile that includes a linear matrix (sensor match to alexa) and the nonlinear 3D Lut (Look for the Alexa). With a Profile like that i could stay in Lightroom in Preproduction where i only use the Sony A1 as i don´t own the Alexa.
That is a display-referred module with non-linear output, so no, you probably don’t want that. All modules have a tooltip that will tell you some essential technical information.
The main scene-referred module for adjusting contrast is tone equalizer.
And remember, the modules are applied in order, bottom-to-top. Anything that’s after filmic or sigmoid in the list will likely cause you problems, since they expect and output non-linear data. In a normal photo workflow, filmic or sigmoid map the scene-linear data to display-referred so that’s not an issue.
I guess I was thinking you would just load your Sony as a DNG with the color checker shot… do the color match function and output that to Alexa with that function, bring your video also to alexa and then your luts as needed …
@priort
The Color Match Function matches the color to stored reference values. It´s not possible to match the colors to a costum reference. Would be a great feature though!
@priort
The Tool matches the Color Checker you shot with your Camera to the values that Color Checker is supposed to show. If there is a little more Green in the Cyan patch than intended the Tool will correct that. Basically it automatically creates a Matrix. You could match two cameras by shooting a Color Checker under the same Conditions with both cameras and then processing the Footage with the Colormatch Tool. But they will meet “in the middle” as they will both be matched to the Color Checker. And you can´t import a Costum Color Checker, which would be necessary. When you want to match one camera to another you need to manually create a Matrix with the RGB Mixer. That way the camera which is your target won´t be touched, it will just be the reference for the other one.
Ya I guess I just figured you could calibrate the Sony but use the gamut and gamma you need as the output coming out of that to match your video camera and then the video footage you don’t want to change colorspace or gamma but you could still color correct it…. I figured this would give you a decent match… I didn’t have any footage but basically tried this with a Sony sample file converted to DNG and loaded… I tried it using either the camera meta data setting or the default for still setting…. Set the output parameters to arri… seemed to get a nice log transformation out of color match… then added a lut to bring it back to 709 and it looked good with that lut…. My assumption being it would look good or as intended with any arri lut … I didn’t have any video to compare with it so I could not gauge this approach for a match to the video. It seems like you have considered this for some time now going back to at least 2022 on the DR forum so I guess you have had lots of suggestions just not one that has panned out yet
@priort
The reason why your test looks good, is that the differences are not huge. But i made a comparison for you. On the left of each patch is the Sony matched with the Color Match Tool. On the right side is the Sony with my manual Matrix done with the RGB Mixer. In the middle is the Arri Alexa Material. As you can see the manual Matrix comes much closer than the Color Match Tool as the Tool doesn´t match to the Alexa Color Science but rather to the X-Rite Color Checker Science. You can still see a small Difference between Alexa and Manual Matrix in the green Patch but it´s almost identical. The Color match Tool an the other side made the Blue Patch brighter and the Green Patch darker, therefore Cyan is almost good but Blue and Green are off. To be fair, the difference is too small for results to be really bad, but too big for a match…
Yes, i started researching this problem a while ago and back then i found the solution to convert the ARWs to DNGs in Lightroom, then importing them in Resolve through the RAW Tab and matching them with the Matrix i created. But it is not a very convenient Workflow and also has it´s technical limitations. The EXR method definitely improves the image quality and will come in very handy when it´s about actually mixing the A1 Material with the Alexa Material.
But there are sometimes month in my work where i only use my Sony A1 and it would be amazing to stay in Lightroom or even Dartable (which grows on me) without transferring the images to Resolve to grade them there. After all Resolve is designed for Video and not for Photo. So my dream solution would be to create a Lightroom Profile that includes a linear Matrix (Technical Match) and the LUT i created for the Alexa (Look). Two Cameras, one Look.
Thanks …I’m curioius what settings did you use for the color match on your A1 when you use the color checker…what gamma and colorspace do you use… for the import and the output from the module
