Reversal Film Support (or workflow)

I’m curious if you’ve developed a workflow for slides inside of NLP. Is there enough interest for reversal film support? Or possibly a new plugin, Reversal Lab Pro?

I tried to emulate a negative conversion by inverting the color of the slide in Lightroom before applying NLP and it looked pretty good. I’m wondering if maybe with native support, colors would look more accurate. LUTs are used for conversion right if I’m not mistaken. If so, would it be possible to support Ektachrome/Kodachrome corrections?

interesting idea.
could you maybe post a comparison of a slide scanned positive and a slide turned positiv with nlp?

What do you want to achieve turning slides to negatives?

NLP uses calibrated profiles and math for conversion of negatives to positives. It would be cool if slides also had that ability as well, to help get accurate color without manual adjustment.

By inverting the slide color first, it can then be processed by NLP, but if an option was made for correcting the color of reversal film instead of a negative, then it could benefit a slide scan/image even more

Well it’s none of my business what you do with your photos however this is comparable the hamster running that wheel …

Slide already is a positive and thus fit for projection or scanning which is basically the same.

True, slides were printed to paper via different processes sometimes however rarely using a negative intermediate (logically so). This is why negative is sometimes called print film and positive slide …

So the only thing one could emulate are printing processes, and papers - this would however leave you with imfinite variables …

So just scan and do your editing in Lightroom or whatever …

Reversal Film is also a transparency film, even though during scanning, you don’t need to invert.

Since NLP can correct faded negative film nicely, then that would benefit reversal as well, no? Editing each manually is definitely a possibility but if what NLP does with calculations on color calibrations and matrixes for various cameras and scanners then it would benefit reversal film immensely if supported.

NLP uses custom LUTs and soon with newer updates, custom matrixes. Without those, getting consistent/accurate color of positive film would be dependent on the skill and time spent on whoever is correcting it. But for negatives, NLP is using math conversions to get you that first conversion before manual adjustment saving you a considerable amount of time.

I have played around with the idea of making a separate program that would deal with positives (both digital and scanned reversals). There are a number of technologies inside Negative Lab Pro that could be very useful for both a digital and scanned reversal workflow (like scene evaluations, normalization, auto-color, gamma adjustments, etc).

Stay tuned… :wink:


You guys are getting me really confused now. What is a digital reversal? How would normalisation, scene evaluation etc differ from other editors like PS, AP etc?

Beside - there is no correct / accurate colour in photography. Did you guys have real darkroom experience before? Each film exhibits different colour dependant on the time of day, weather and general lighting conditions. That’s why you had those daylight and tungsten balanced films - to roughly correct the balance for light source …

Then the enlargers had different light sources (changing with age etc.) not to mention CMY or RGB colour correction … Lastly you had the process and the paper. There were creative decisions to be made just like there are today with PS or other editors (yet more rudimentary of course) …

In fact the closest one can get to “correct” colour is a projector with a dia positive slide or a scan with an equivalent light source without any tweaking.

So the negative inversion software is basically always just what scanner apps did in old days and mostly it is dealing with the troublesome “orange mask” via normalisation or colour subtraction …

Saying that one inversion is more correct than the other is silly as there is no correct positive reference. One can only say the inversion is corrected for orange mask and white balance and this can be way of from what a print would produce … Negative film was not meant to be watched but printed.

I am not trying to diminish the worth of porting the neg reversal to Lightroom or other modern photo editors - it severely aid DSLR scanning which is sadly becoming the only feasible way to scan (however far from best way).

Anyway good luck developing the plugin!