I have a x-rite color checker and tried to use it in Rawtherapee but because I’m working in a linear workflow the results I got from applying the color profile were incorrect. When running a photo of the color checker through the Camera Calibration software I have to use either a DNG file from Adobe or a TIFF file that is coming from Capture One. Both of these application apply a curve to the images which makes them non linear.
Is there a way to correct the colors from within Rawtherapee using a color checker? Or is there maybe an alternative product that I can use that can create color profiles using TIFFs that are exported from Rawtherapee?
Rawtherapee is one of the few products that can correctly export a linear photo. Adobe RAW and Capture One definitely do not.
I think in RT you use the “save reference image” in the color management tab…this should give you a linear tiff… if making a dcp the advice in the documentation says don’t apply wb and for icc do apply wb…I think I have seen the whole process in RT documented…
Thanks! The Lumariver program based on dcam seems very useful. It’s not cheap for the limited use I need it for but will consider buying it.
The Adobe profile editor is the RAW converter I think you mean. That uses Adobe Camera RAW to create a TIFF or a DNG so that will have a curve applied.
not sure if this is what you are wanting for x-rite??
And the profile editor is a powerful tool that can apply a linear profile to a raw by editing and creating a custom dcp file from any dng file…
You can also use a color checker with it…its DNG convertor and the Profile editors are free not FOSS but they can be tools you use to create dcp files for RT…
So I went to the GIMP and opened the same image. Then selected color>levels. The middle pointer in the GIMP’s levels is actually gamma, default = 1. If I have opened an image that has been 2.2 gamma’d, I can make it sorta linear by setting the middle pointer to 1/2.2 = 0.45.
Thanks guys for the suggestions. I ended up buying a Lumariver license.
I think I have a good workflow now that is linear. I’m not an expert in tone mapping or color correcting but I think I’m there. I use Rawtherapee to export a Reference image, which has a green tint because of the nature of the camera sensor, load this into Lumariver and from there export a ICC profile. I load this into Rawtherapee, see the changes and white balance it. They are very small but good to have nonetheless.
I sent Calibri an e-mail that it’s ridiculous that their software only supports DNG files and TIFFs (but TIFFs from Rawtherapee don’t work). It’s just a very limited and crappy piece of software. For this reason I have to buy extra software and pay 120 euros for something that should have been included with the color checker card. I think your probably better off getting a color checker from aliexpress and buying the Lumariver software (if it supports one of those cards)
Don’t underestimate the quality of China these days. I’ve had multiple products from the US and they all sucked. Often it’s marketing that makes a good product, especially in the US.
I thought that for matching images, it doesn’t really matter if the color checker colors are entirely accurate and only consistency mattered. For this use case wouldn’t a cheap chinese passport work?
If they provide the .cie file containing the RGB/XYZ measurements for their patches it should work OK. That is, if you trust their measurements. Above all, Do Not use the software-provided .cie files with them, as those are likely for the xrite patches, not the same formulation.
It would be interesting to photograph both cards and put each color right next to each other. If they are exactly the same, or at least to the eye, it should work out fine.
Well lumariver has a lot of options if you decide you need them in the future. For what you ended up doing you could have used Argyllcms. There are a couple of GUI for it and you can create a variety of ICC files … If you want a link I can share and you could compare results…
