Automating my 35mm film scanning pipeline (shannadige.com)

47 points by shannadige a day ago

hankbond 20 hours ago

Very neat. I have a love-hate relationship with a unique type of digital sensor called the Foveon X3, which needs a particular (very sluggish and limited capability) software made by Sigma to convert the RAWs. Recently I have been using AI to create a converter that processes the RAWs in a similar fashion with some improvements.

This is one of those cases where its a means-to-an-end (I just want to take more photos without being bogged down) and less of a project for me to learn how to reverse-engineer and design signal processing pipelines. I am very grateful for what recent models are enabling me to do.

10729287 15 hours ago

Everyone has a love/hate relationship with Foveon, that's the beauty of the sensor isn't it ? Would you mind sharing your project ? That's awesome. Have you been able to compare crispness of files ? Dng compatibility from latest cameras, although it results in huge files, was pretty useful but files were not as sharp as native X3F developed in Sigma Photo Pro.

devindotcom 19 hours ago

Remind us what the Foveon sensor's quirk was? Something in the subpixel layout as I recall. A non-bayer pattern since abandoned and largely unsupported, yet effective somehow. But maybe I'm imagining this.

10729287 15 hours ago

Foveon sensor is composed of three Red/blue/green layers, so each pixels know exactly its color, while the Bayer sensor used by other manufacturers is composed of pixels that are either red, blue or green, and that implies some reading out of its color and its neighbour's one... and some glitches (typically moire or purple fringes). In order to reduce those, a Low-pass filter that blurs the picture a little bit is added on top of the sensor. Therefore, foveon pictures are way sharper, with true colors. This is the theory for colors... in fact it's a very hard to tame sensor and results can be very random. Plus the cameras are very slow because they have to process 3x more information. Sigma being a very very small company versus the other big guys, their R&D is limited. Still, it's a very nice camera to use for geeks who takes time to understand it. You hate it or love it. No in-between.

dylan604 an hour ago

What improvements have you made? Processing RAW sluggishness was always an issue from de-Bayering. Before RAW, my hell was DPX image sequences. This was pre-SSD, so I/O was painful opening/closing individual frames in realtime. The best improvement of processing RAW I've experienced was NVMe SSDs.

Noaidi 20 hours ago

This is just depressing to me having literally grown up in a darkroom.

"For years my process looked like this: load film and take photos, ....[blah blah blah]... the exported image."

"At first this was an exciting process for me. Then as the number of rolls increased, so did my effort to do this for 36 frames per roll."

I shot black and white film sine the 70's, medium and 35mm. I would develop the negatives and prints myself. The complete process was a joy. I never printed every shot, but I put care into each shot I processed. I was careful when I took a photograph, because the cost limited how much I shot. This made me a better photographer.

I later started scanning my film with a Nikon CoolScan (this was in the late 90's) and i already started hating it. Then I started full digital and now I do not shoot anymore (I was semi professional with Art work published in national magazines).

"My part is now the part I can thoroughly enjoy, which is looking at the results I’ve snapped and finding inspiration to snap more."

Why do any of this just shoot digital if you do not care about the process?

hankbond 20 hours ago

Some aspects of the process seem more like labor than a form of self-expression. I think if you are into the limitations of shooting film photos it makes sense.

wkjagt 5 hours ago

When I showed my Konica Hexar to a younger colleague, he said, but how do you get the pictures into the computer. It was like a world opened for him when I said that I don't.

ares623 19 hours ago

I agree in part, in that it is sad that this person does not have access to a darkroom. As someone who is also now shooting film and then camera scanning, I would love to have access to a darkroom. It's just a compromise film shooters have to make, and often at no fault to them. It's either too expensive (which the negatives already are), or too far away/too big to fit in modern homes, or more likely both.

We're just grateful that film is still available at all.

topper00_raptor 9 hours ago

nice work on the website, micro animation and the dithering effects are clean!

m463 3 hours ago

weird, my cursor disappears over that website.

canucker2016 44 minutes ago

website is actively setting the cursor CSS style to none.

Very user-hostile.

dylan604 10 minutes ago

It replaces the cursor with a custom one. It's not removing the default to just remove it.

vivzkestrel 16 hours ago

- https://shannadige.com/blog

- blog page dont work

ravila4 a day ago

Interesting project! I scan 35mm and medium-format film with a mirrorless camera, macro lens, and Lomography film holder, then convert with Negative Lab Pro in Lightroom. I’m happy with the results, but the Lightroom subscription has me considering writing my own converter.

Could you share more about your NumPy pipeline, or publish the code? I’m particularly curious about how you use the blank film reference and roll-level measurements to handle the orange mask, color balance, and tone curves. Do you use camera/scanner calibration profiles or film-stock-specific adjustments, or estimate everything from the scans themselves?

Also, your screenshot appears to show an OpticFilm 7400. Would you recommend it, and roughly what did you pay? Have you tried camera scanning? I’ve been considering automating film advance and capture on my setup, but consistent color conversion is the part I’m least confident about.

dylan604 a minute ago

A colorist I worked with did something similar by using reference film stock of the same film that was being scanned. This was anime 16mm film prints from the 80s that had been scanned multiple times and color set on arbitrary decisions by who ever was working with the film at the time. After using the reference stock to base decisions, the director said it was the closest he had seen to what he wanted.

ravila4 a day ago

To reiterate, those were legit questions. I used voice dictation to my phone, with an app that transcribed and formatted my message.

bbatha 20 hours ago

You should check out the negpy project. It in my view has the best inversion process. It claims to emulate the whole analog print chain in the inversion process. They have a fold works cited.

It also automates most of the process. It works with SANE, some other legacy scanners, and camera scanning. It can even do trichrome scans automatically.

chickensong 19 minutes ago

Thank you!

mattz56 9 hours ago

I don't have a public writeup, but the general approach for orange mask removal is: scan a blank unexposed frame from the same roll, take its per-channel mean as your reference white, then divide each pixel by that reference per channel before doing anything else. That normalizes the mask out instead of trying to subtract a fixed color. After that, a per-roll linear stretch (black point from the darkest scanned frame, white point from the lightest) gets you a rough base. Tone curve is the hard part: NLP uses a nonlinear S-curve tuned per stock, and matching that from scratch means a lot of trial and error with reference images you know the expected look of. If you want a quick win before rewriting things, Lightroom lets you write develop settings to XMP so you're not locked into the catalog even if you cancel later; the actual RAW/TIFF processing engine is what needs a subscription, not the metadata.

dang a day ago

Can you please not post AI-generated or AI-edited comments to HN? It's not allowed here - see https://news.ycombinator.com/newsguidelines.html#generated and https://news.ycombinator.com/item?id=47340079.

Of course, it's impossible to know for sure what was LLM processed or not, but some of your posts (like this one) have been getting classified that way.

dekhn a day ago

It is a very sensible and reasonable comment- literally all questions I'd want to ask to replicate the setup, in a format that's easy to parse. If the author did use LLM it did not substantially alter the content of their question.

EvanAnderson 20 hours ago

ssl-3 19 hours ago

For whatever it's worth: It's definitely phrased a bit strangely but it passes my own sniff test. If they really are using a dictation-oriented method for getting text into a box (as they wrote in a followup reply to themself) then that may adequately explain the strangeness.

There was a time when scanning and [photographic] printing of 35mm film negatives was what I did for a living; it's likely that I've touched more film than most people ever will. I think they're asking questions that are a good combination of solid, thoughtful, and practical.

black_knight 42 minutes ago

tptacek 18 hours ago

dekhn 19 hours ago

Dang, would you reconsider your message here? I think it was uncalled for and chilling to legitmate discourse.