I have two scanned slide photos in TIFF format which were taken in short succession (one after the other). They are sunset shots using a filter to accentuate the color of the sky and silhouette the subjects in the foreground. One image has good color and brightness, while the other is dark. I don’t know if the difference is due to processing, age (the two slides are over 50 years old) or something else.
I’d like to brighten the dark image to closely resemble the “good” image. From my simplistic view, it seems that if I could copy the histogram of good image to the dark image then it would give the results I’m looking for. Is it possible to copy and past histograms in Raw therapee? Am I going about this all wrong?
Hello, as far as I know you can’t copy a histogram in RawTherapee. But you can copy the profile of the “good” photo to the dark photo. In the Navigator, right-click on the good one, choose Profiles (or something like that) and say Copy profile. Then right-click on the dark one, again Profiles, then Paste profile. Does that help?
Do the original scans show these brightness differences, or are they introduced while editing in RT?
Thanks for the reply. The brightness differences are in the original slides. I haven’t modified the good photo to increase it’s brightness, so I don’t think copying its unmodified RawTherapee profile will help.
I guess I’ll try to modify the RGB curves of the dark image by hand to match the good image. Hopefully I can find a good RGB curves tutorial that can help fine tune the curves.
No, they were scanned individually. The dark slide is visually darker than the other, the difference didn’t happen as a result of the scanning process. I’m a RawTherapee novice (in case you couldn’t guess). I’m trying to find a good primer on using the RGB curves to modify the histogram. Hopefully I can get a good result.
I’m not sure if RGB curves is the right tool to alter exposure. You better start with the Tone curve tool.
Eight (!) years ago I wrote a little artice about how to use tone curves in RT. The program has changed a lot over time, but the basics of tone curves still apply.
If you have a lot of images and you are just trying to exposure match them you could try DT. It can sample a photo and then it will adjust subsequent photos to try and match them from that key image…
The video is old now so the feature is in DT… Ignore if your preference is to stick with RT for a solution…
