Film simulations from scratch using Python • Hacker News Board

Re: Film simulations from scratch using Python

#31

Post by xyzzy_plugh » Wed, Apr 28, 2021, 8:37 PM UTC

yesimahuman wrote: post #24

CarVac wrote: post #22

Earlier quoted context omitted.

The Fuji film sims are pleasing to the eye but by no means are they close to their namesake film stocks.

Yea I think that's the primary issue to me. The Acros one is pretty good but the others leave a lot to be desired. The Velvia simulation is basically just a high saturation mode without the magic of Velvia. Classic Chrome doesn't look like any film stock I'm familiar with. Compare this to RNI film's preset pack for Lightroom which I find are much more interesting. I think a big reason they won't ever come close to tr…

> Compare this to RNI film's preset pack for Lightroom which I find are much more interesting.

Sure but now you're paying a yearly subscription for Lightroom and buying third party presets. The Fuji profiles are free with the body and are pretty good for the vast majority of users.

Besides if you're developing from raw anyways, you probably don't care about the Fuji sims in the least. It's apples to oranges. For more casual JPEG shooters they're easily accessible and look great.

Re: Film simulations from scratch using Python

#32

Post by justtocomment » Wed, Apr 28, 2021, 9:45 PM UTC

yesimahuman wrote: post #17

The Velvia simulation at the end is very good, nice work! As someone that still regularly shoots film and also owns a Fuji X Series camera, I don't find the film simulations that Fujifilm puts in the X models to be any good, so I feel like there is still a lot of worthwhile work to be done here.

I enjoy my Fuji X system camera and the colours it produces. Sometimes, however, I'd like to do some RAW processing in Linux (Darktable) - but of course this means that I lose in-camera film simulation.

Since the camera can store the same photo in 2 different formats (RAW+JPEG), I'm wondering if it would be worthwhile to use a lot of these file pairs to try to get a LUT allowing to map Fuji RAW files to Fuji-Like JPEG results.

Is there anybody knowledgeable here to tell me whether this approach is doomed from the start or if it could be promising?

Re: Film simulations from scratch using Python

#33

Post by nwiswell » Wed, Apr 28, 2021, 11:17 PM UTC

I thought this was about thin film simulations based on the title :)

There is a wonderful transfer matrix method library in Python for reflectometry simulation too, if that's what you were hoping to find.

https://github.com/kitchenknif/PyTMM

Re: Film simulations from scratch using Python

#34

Post by kelsolaar » Thu, Apr 29, 2021, 6:01 AM UTC

zokier wrote: post #6

kelsolaar wrote: post #4

The article title is a bit misleading, I was expecting actual simulation of film stock processing and rendering in Python. Here this is more about 3D LUTs usage, not much to do with film simulation itself.

Misnomer or not, 3D LUTs are what the industry means when they say film simulation, maybe with some grain effects sprinkled on top.

Well, not really, 3D LUTs are just 3D LUTs, they are typically just a mean to represent expensive functions from a performance standpoint with a fast alternative, or a way to obfuscate proprietary functions with a single table. Whether they are used to carry a film look is entirely dependent on what the 3D LUT models, and certainly not every single one of them is a film look. Disclaimer: I work in the industry and produces 3D LUTs as part of my job.

Re: Film simulations from scratch using Python

#35

Post by yesimahuman » Thu, Apr 29, 2021, 5:24 PM UTC

xyzzy_plugh wrote: post #31

yesimahuman wrote: post #24

Earlier quoted context omitted.

Yea I think that's the primary issue to me. The Acros one is pretty good but the others leave a lot to be desired. The Velvia simulation is basically just a high saturation mode without the magic of Velvia. Classic Chrome doesn't look like any film stock I'm familiar with. Compare this to RNI film's preset pack for Lightroom which I find are much more interesting. I think a big reason they won't ever come close to tr…

> Compare this to RNI film's preset pack for Lightroom which I find are much more interesting. Sure but now you're paying a yearly subscription for Lightroom and buying third party presets. The Fuji profiles are free with the body and are pretty good for the vast majority of users. Besides if you're developing from raw anyways, you probably don't care about the Fuji sims in the least. It's apples to oranges. For more…

Sure but I'm talking about the pursuit of the best quality film simulation, not merely a good enough solution for most people (which X definitely is, to be clear!)

Re: Film simulations from scratch using Python

#36

Post by benEatsWorld » Fri, Apr 30, 2021, 7:46 AM UTC

CarVac wrote: post #22

xyzzy_plugh wrote: post #21

Earlier quoted context omitted.

> I don't find the film simulations that Fujifilm puts in the X models to be any good I feel like you might be in the minority, I continually hear overwhelmingly positive remarks regarding Fuji's film sim. I'm not aware of anything comparable at that price point, and I have yet to see any non-pro film sim come close to the stock Fuji sims.

The Fuji film sims are pleasing to the eye but by no means are they close to their namesake film stocks.

I think they are kind of lo-fi copycats of the RNI film profiles. The Fujifilm's Classic Neg looks suspiciously similar to the RNI's Fuji Pro 160ns while having visibly poorer quality in the shadows and dark skintones compared to RNI.

And the RNI profiles are definitely the best in class and built after the real emulsions very carefully, at least I can confirm that for Fuji Pro, Fuji Superia and Kodak Portra & Ektar - the stocks I'm very familiar with.