Film negative tool for color film only?

[lummukka]

Hi, I have been trying to understand the film negative tool but can't find in the documentation if it's meant for color negatives only (with the orange mask) or does it also work for B&W negatives?

So the request from me would be to clarify this in the tool itself / documentation and eventually provide support for B&W negatives if not already there.

Or should I invert the B&W negatives with curves tool only?

Br Vesa

[rom9]

Hi! Indeed, the film negative tool was created specifically to deal with color negatives (i agree that it is not stated clearly in the docs and labels). This is simply because with B&W, the same result can already be achieved with existing tools (the tone curves as you mentioned), and i really don't see what the film negative tool could do to improve that. It's possible to use the tool to invert B&W film, by just setting both the "ratio" sliders to 1.0 (that will apply the same power curve to all three channels), but... is it really worth it? You will have to use the tone curves anyway to fine tune the result... So, my answer would be: yes, use the tone curves for B&W.

I would re-label the tool to "Color Film Negative" and adding a dedicated "B&W" paragraph in the wiki, with a brief description of how to do it with tone curves (i can write something down this weekend). How about that? :-)

alberto

[lummukka]

Hi Alberto, thanks for replying back. As long-term Rawtherapee fan I see two alternative approaches. A) would be like you say label it as "Color Film Negative" + new paragraph or B) Add a small switch in the tool to toggle between "Color Negative" for handling the color stuff+orange mask or "B&W Negative" for just the inversion.

Br Vesa

[rom9]

Actually, on second thought, you convinced me :-) I've scavenged an old BW negative and tried to fiddle with it, and i have to admit (although you can invert it just using the tone curves, and it's much easier than dealing with color negs), that it's not very intuitive, and adjusting the tone curve is a bit tricky. Also, i'm currently doing some experiments with color negatives regarding the correct handling of over-exposure, and these could also benefit B&W negatives, so with my next major change, i'll provide an option for B&W.

In the meantime, maybe there's a quick and easy solution: i could create a new bundled profile, called "Film Negative - B&W", which presets the Red and Blue ratio sliders to 1.0, and enables the Black-and-White tool. This way, just selecting the bundled profile would give you an almost finished image with one click, and you would only need to do minor fine tuning, without having to flip curves, etc.

How does that sound? ;-)

[lummukka]

That sounds fantastic!

[rom9]

Just pushed to dev ;-)

I would leave this issue open as a reminder for myself to implement something more specific in the tool itself (like, disabling the color sliders, avoid unnecessary computations, etc.). Unfortunately, this won't happen soon, as i don't have much time... Hope this bundled profile can help in the meantime :-)

[tedsmith]

Hi. Some might remember I started what turned out to be a big post about the film negative feature back in 2019. I was just checking back to see how things progressed and wanted to ask if it still only works on "digital photos" of negatives as still stated here https://rawpedia.rawtherapee.com/Film_Negative or does it now enable the user to pass a raw scan from tools like Vuescan? I ask I still don't do the whole digital photos of a negative technique and use an Epson v550. Thanks

[Lawrence37]

@tedsmith If the scans are in an image format supported by RawTherapee (dng, tiff, png, jpeg, etc.), the film negative tool will work.