P: Ability to invert negative scans to positives (color and black-and-white)

There's always a ton of people looking to get Lightroom to do more than it was built for. This is because the database/organization in Lightroom is the best game in town. We all gravitate to it and want to put all our files there. So here's another request from left field that might not be so wild.

I would like to see an Invert button, RGB/LaB curves, RGB Levels, and Linear raw editing in Lightroom. I know I know. It's not the way Lightroom works; Lightroom is for raw cameras, etc,etc.

BUT!

1. Nobody is making scanners anymore.
2. There are billions of pieces of film that still need to be scanned.
3. 21 megapixels (and up) + a 100mm prime macro lens do a handy-dandy job of copying 35mm film at 4000dpi resolution. (Hass. just came out with a 200mpx camera. It is drum scanner like.)

So . . . . soon (like in 4 or 5 years) this will be the way pros (and LOC, and a handful of major archives) scan film. And the software that will support those raw files? Right now it's Bibble 5. Lightroom doesn't have acceptable chromatic control.

If Lightroom could interpret a RAW file in a Linear fashion (ie: not messing with L and saturation values but keeping them in line), and give us RGB curves and levels, we could very quickly build out neg profiles based on published Gamma curves for various films types. This would quickly make LR the defacto input workflow for both camera scanning and raw tiff files from every scanner out there. It already works perfectly for BW film. What about color negs?

The raw controls that LR has, already, would make it superior to all other scan invert apps. Stacking Recovery or Fill control on top of a perfectly inverted raw color negative scan would be very sweet indeed.

This would also have the effect of making Lightroom the main starting point for any photographic workflow. It would quickly populate through every fine art photo department in the country (yes, cneg film is still a part of the curriculum). A vast new generation of students would be introduced to Lightroom as a required software just like Photoshop. Right now ACR is free. Why pay for Lightroom?

The "raw scan" competition is Bibble5, Silverfast, and Flexcolor. All 3 of these applications don't interact with Photoshop in any meaningful way and Bibble is the only one capable of interpreting raw camera scans.

My two cents,
Walker Blackwell

Jeff, writing a profile is much less "kludgy" than inverting. You can invert already just by inverting the tone curve in point curve mode (put the lower left point in the upper left and the upper right point in the lower right).

This is an amendment to my original post:

Everyone seems to be making this **way** too complicated. Look, at its heart, every digital image file is a matrix of rows and columns representing the illuminance values (e.g., 0 to 255 for an 8-bit file) for each pixel in the sensor (a physical matrix array of sencels). In a color file there are, in essence, three matrices, one each for R, G and B values. And yes, I know that there's a Bayer array of sub-sencels that makes it a bit more complex, but I'm simplifying here. That level of complexity doesn't change the basic concept.

In a B&W image, regardless of whether it's a negative or a positive image, the three matrices of R,G and B values are combined into a single set of gray-scale values using a weighting algorithm. (I'm simplifying here. NIK SilverEffex Pro allows the user to select how each R, G and B channel is weighted and combined to produce the final gray-scale matrix, but we don't need to concern ourselves with those details, here.)

In essence, to convert a B&W negative image to a positive image one merely needs to subtract each matrix value from 255 (assuming an 8-bit file for this discussion). Zero values become 255, values of 255 become zero, and so-on in a linear fashion for in-between values. It's simple, basic matrix math. I do mean "simple," and I do mean "basic." The only complexity may be the different formats that proprietary RAW formats use to store the matrices, but these differences are certainly well-known, otherwise current development adjustments could not be done. This is not rocket science.

Once that simple matrix subtraction process is done, one need only decide whether to save the result as a virtual copy, or as an overwrite of the original file (in appropriate RAW format, without changing other RAW data, of course). The user could select which option they prefer via simple check boxes. The user then proceeds to use the regular development sliders **in normal fashion** on the virtual copy or the overwritten file from there on out. Problem solved....

Adobe, please don't force your users to tie themselves in knots with kludgy solutions, when a simple and elegant solution clearly exists, as it does in Photoshop. The basic problem is that you (Adobe) need to decide that this functionality is a high enough priority to devote limited programmer resources to its solution. That's where feedback from the user community plays an important role. If you're a user who really wants this functionality, then you need to let Adobe know that you want it. It's that simple.

Just FYI, I have a BS in Physics (UC Davis, 1969) and I'm all-but-dissertation for a Ph.D. in vegetation ecology (also UC Davis), where I worked extensively with matrices of species=by-plot and environmental variables-by-plot data. I also managed projects to produce digital vegetation maps using low-elevation (airplane platform) digital imagery. I am familiar with matrix mathematics/algebra in the analysis of both types of data matrices.

Which scanning software do you use?

The "right" was to implement this as a user is to develop a new profile using the DNG Profile Editor, which Adobe provides for free.

This capability exists in Lightroom already, because about the only way to do it is to use a develop preset.

You would have to cook up a preset for every process you want, of course.

See here (though there are others, if your web-fu is good):

http://www.lightroomforums.net/archiv...
http://photography-rod.blogspot.com/2...

Personally, I've found that the scanning software I use with the process/negative specific plugins makes perfectly good raw positives.

I would also appreciate this feature as well as an extension to colour C41 film to remove the orange mask.