And an idea popped into my head: could we do this accurately in darktable? I believe we can (or at least come close) and have relatively accurate camera independent film emulations saved as presets.
Please correct me if I’m wrong. Disclaimer alert, I know nothing of negative scanning. This is just an idea that I think would work.
After the previous video, I watched this:
There @anon41087856 explains how to create a custom WB and color calibration profile for your camera with a color checker.
To scan the negatives, the guy from “The art of photography” uses a Nikon Nikon ES-2 film scanner. I don’t know if there are any generic ones, but let’s assume we use this one.
Steps to create the film emulation preset:
First of all we need to create a custom WB profile for our camera/lens combo like Aurélien showed.
Then we need to shoot an image of our color checker. He recommends natural light, avoiding color casts from surroundings. Would studio lights also work? I would imagine completely stable lighting conditions would be best for this process, so artificial light might work better.
Take a picture of the color checker with an analog camera with the film that we are trying to emulate in the same lighting conditions, and ideally with the same lens.
Create a color calibration profile like Aurélien showed (from the digital image of our color checker). This, in combination with the WB preset we created earlier would give us very accurate colors for our Digital camera/lens combination in that lighting environment.
Scan the negative of the color checker shot with the film camera under the same light it was shot with with the Nikon attachment.
Use Negadoctor to invert the negative
Apply the WB/Color calibration presets we previously created, so that our digital camera/lens combo doesn’t alter the colors of the negative.
Add a new instance of Color calibration and calibrate it again (this time using the color checker shot with the film). Instead of committing the changes, the values need to be reversed (positive values turned negative and viceversa). Then we manually type in the reversed changes and save our profile. The reason for this is that this time around, instead of trying to get accurate colors, we are trying to record those from the film, we are recording the deviation the film has.
If I am right, we should have created a camera independent and accurate film emulation profile for darktable.
G’MIC Color Presets with lut 3D module at the last module gives me pleasing results, but I’m not under the impression that it will be a faithful emulation. These HaldCLUT files knows nothing about the starting point of my image.
Your idea sounds very interesting. I believe IT8 would be a more suitable target for this application. Torger’s site is helpful when it comes to these matters. Also makes me miss support for dual illuminant DNG/DCP which gives good camera calibration results with shots at only two color temperatures.
I suppose when you start pulling sliders in your modules, your raw file will not respond to these changes as film (or paper) does to light. But the same would be true for scanned and digitally post-processed film. And, still orders of magnitude more accurate than the “blind” hald.
Re: the video. Seems the good old influencer LR preset business is still flourishing a near decade after VSCO Film was released.
Hi all,
I wish someone could fork an open FOOS scanning software that could be used on various scanners. I have an Epson Perfection V850 and the Epson software, Vuescan and Silverfast all do a pretty crap job in my opinion. I used to have a Canon 9000F scanner and that Canon software was much better at scanning negatives. Scanning photos is great by all software but negatives are a nightmare.
I can only assume that with a good light source, the better the target, the better the calibration profile will be.
That would be the point, right? This film emulation profiles would in theory give you the colors of a particular film, but you would still retain all the advantages of digital being able to go in there and tweak exposure, contrast, saturation, local contrast, work on individual colors… you name it.
Unfortunately I don’t own a device to calibrate my screen, a color checker or a film camera, otherwise I’d already be trying this out.
The problem with the idea (and any film simulations ) is that there is no one ‘true’ look for a film negative. The colors can change quite a lot by just a small change in on of the multipliers in negadoctor for instance .
Doesn’t mean it can be a nice idea and can produce useful results , it are all tools in the arsenal, right?
Well, you are right, especially in terms of contrast raw developing software like darktable gives you a ton of options that you wouldn’t have with film. The part that I find particularly interesting is that happy medium between the convenience and flexibility of shooting digital, but being able to have an accurate preset with a particular film stock’s colors as a starting point if that’s what you are looking for.
I am hoping that @anon41087856 or one of the devs sees this post at some point and comments on the process I outlined to see if it would actually work. If so, perhaps some people in the forum actually have access to the hardware that’s needed to create said film emulations.
In the past they have been created in the color lut module…I am not sure of the process…if it was manual or darktable-chart was somehow leveraged… There are a few fuji presets in there and others are available…most notably Site is undergoing maintenance They are available in two flavours it seems…Luts and styles…the styles you could easily tweak as they use tone curves https://github.com/t3mujin/t3mujinpack
I don’t like to post negative comments (forgive the pun), but this proposed workflow for creating custom profiles for films depends upon having access to the original film stock to shoot a color checker. The problem is that most scans are from films shot years or decades ago and we have to depend on the scanning software inverting the colours into a correct looking image. One technique I use is to scan as a 16 tiff, low contrast image and ensure the darks and the highlights are all within the histogram. Then I let Darktable or GIMP work their magic to fix this flat image. For various reasons I find GIMP my preferred program for restoration work. Another method I have tried with a reasonable degree of success was to scan the negatives as a positive so the scan still looked orange based and then employ negadoctor to do the inversion to real colours. Negadoctor shows a lot of potential here, but maybe needs some continued improvements, which may be the presets of ‘accurate’ film emulations that you are asking for. Currently I am scanning hundreds to thousands of negatives and I really would appreciate good scanning software and it just doesn’t seem to exist for my Epson Perfection V850.
I think we might be talking about different things. The color calibration presets I’m talking about only need scanning to get access to the film’s colors, so that they can be translated into said profiles via color calibration. My goal is not to shoot film, but to use film’s colors in my digital pictures.
It seems you are referring to certain features you miss in negadoctor for scanning your images.
The old rni legacy stuff for Lightroom/ACR came with specific camera profiles and then presets to use on top of it .
One of the reasons I liked them in my head: they seem to at least understand the starting point for your images, which makes more sense in my head to get to a certain wanted result. A lut can only generalize.
I don’t use film emulation anymore, so I don’t know how it advanced over the years. I still like to use a lut or preset every now and then to see if it does something I like , or for inspiration . How realistic it is, i don’t care
