Rawtherapee - How do I enable the film negative tool please?

Hi

I was told about RawTherapee by some fellow film photographers. I’ve been a film photographer for years and years and have typically used other tools in my workflow for negative processing, but colour film has been a challenge so I wanted to give RT a try.Especially since the newly introduced ability to process a negative scan.

I use Linux Mint and have version 5.7 installed (Version: 5.7, Branch: releases, Commit: f335efe). I add my raw negative scan (note this is a true raw scan, without inversion) that I captured using VueScan and Epson Perfection V550. However, when I go to the “Raw” toolset where I gather the new film negative tool is positioned, the entire panel is greyed out. I can’t select anything.

A fellow user said it was because my scan was a TIF scan, so I changed the file extension to DNG. But same issue. See screenshots.

How do I enable the film negative tool please?

Hey

Start by reading documentation, particularly the Film Negative page and the Getting Started page:
http://rawpedia.rawtherapee.com/

Thanks for that link, which sadly I have already read via the “Documentation” button on the home page. Back then then I got as far as :

  1. Open a raw photo of a negative.
  2. In the Raw tab, activate the Film Negative tool."

I spent some time trying to find out how one “activates the Film Negative tool”, given the entire “Raw” pane is greyed out. So I’ve re-read it again following your nudge to do so, and I still can’t find the answer. I must be missing the obvious I guess.

You file is tiff, not a raw file. Just renaming the extension to dng will not change the file itself.
The tool will activate only when a real raw file is detected.

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@ted_smith

The tool supports raw photos of a Bayer of X-Trans sensor. Other raw types and non-raw formats are not supported.

Hi @ted_smith and welcome!

Would tab Colour/Film Simulation/Negative help you?

Have fun!
Claes in Lund, Sweden

I did miss that, although I think I probably just didn’t understand it. I don’t know what a “Bayer of X-Trans sensor” is, but mistankingly assumed that a raw uncompressed scan from the Epson would be one of them, but it must not be. UPDATE : just googled it, and it seems it is a CMOS sensor capture of negative (https://en.wikipedia.org/wiki/Fujifilm_X-Trans_sensor)? So the negative converter is for converting DSLR captures of negatives, as opposed to traditional scans? Unfortunately I don’t have any DSLRs so I can’t do that.

It looks like RT might not be for me, just yet. But interesting to see its capabilities. Windows and Apple users are using Lightroom in droves, using this plugin called Negative Lab Pro, that comes with a $100 price tag. I don’t have Lightroom or that plugin, and have been using a professional lab for colour work for years. I think for now I will continue to do so, but it would be great to see an accurate inversion tool for RT that works with standard TIFF flatbed scans, and so on.

That’s a typo of => or

Exactly!

OK, that answers my questions then, thanks. So it’s certainly not for me sadly. The idea of rigging up DSLR on tripods over lighttables to take photos of my negatives just seems foreign to me. I know lots of people are doing it, but I think I’ll just stick to my usual workflow for now. Thanks again.

Noone said you have to go the vertical way. The horizontal way also works. But of course it’s up to you :wink:

I don’t have a DSLR at all. So vertical or horizontal is not going to work for me. :slight_smile:

VueScan can scan images to DNG.

True. But unless I have mis-understood, I thought the resulting file had to be one captured using a DSLR CMOS sensor or similar to be used with this new functionality in RT??

I haven’t tested it to see if it works, I was only commenting that it is possible.

Vuescan can also “scan” (or rather process the raw file coming off the camera) from various camera raw formats. I’ve done a bit of testing on colour negs with Nikon .NEF files and have been able to get reasonable results sometimes but not others. Vuescan seems like it hasn’t changed a lot in 20 years and the controls are rudimentary compared to RawTherapee. I’ve done a ton of DSLR scanning on colour trannies and B&W negs with excellent results with RT, but colour negs have always been a greater challenge. The new Film Negative feature of RT makes the job easier, still needing a fair bit of fine tuning the colour temperature and tint, and the results are much better than I was able to achieve with Vuescan.

Sure, but the poster said they don’t have a DSLR. That’s why i suggested they give the vuescan dng a shot

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Tripods are horrible for that task as they are so hard to adjust. A copy stand is the way to go, but good ones are expensive. I’ve used a small LPL copy stand for a few years, but recently figured out a better way as shown in these photos. Most photographers already have a good ball head and possibly an Manfrotto Super Clamp. After that you just need a wooden base and some inexpensive plumbing supplies.

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Bayer or X-Trans>

A digital camera has a uniform sensor composed of millions of photosites. To get color, the sensor is covered by an array of tiny red, green and blue filters, one over each photosite. This is the “color filter array”, or CFA. These CFAs come in two general patterns - the “X-Trans” pattern, used by Fujifilm, and the “Bayer” pattern, used by everyone else.

Bayer-vs-X-Trans

The Film Negative tool in RawTherapee 5.7 requires that the raw file uses one of these two, for reasons.

There are also Foveon sensors which do not have a CFA, but RawTherapee 5.7 does not support those at all.