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Film simulations from scratch using Python

kevinmartinjose.com

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Re: Film simulations from scratch using Python

#21

Post by xyzzy_plugh »

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 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.

Re: Film simulations from scratch using Python

#22

Post by CarVac »

xyzzy_plugh wrote: post #21
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 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.

Re: Film simulations from scratch using Python

#23

Post by jbunc »

It's hard for me to see this as doing a good job of simulating film when it doesn't mention grains. Film has a granular structure where each "pixel" is a grain (crystal). Film is essentially already digital, but with a higher count of less regular pixels.

Re: Film simulations from scratch using Python

#24

Post by yesimahuman »

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.

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 true film is that proper film simulation is likely lossy (grain/etc) which no digital film simulation in a camera is going to risk.

Re: Film simulations from scratch using Python

#25

Post by rasz »

app4soft wrote: post #2

> Right – the original image, Left – the image with... Few issues on this site: 1) "Right" and "Left" are wrongly mapped (i.e. "Left" — is the original image in all cases). 2) On 1280px width screen pair images shown in vertical order, instead of horizontal.

3) In Chrome Left and Right image sizes are misaligned by couple of pixels (scaling issues?). I experimented a little and

    div.jx-image.jx-right img { right: 0; }
seems to be the culprit

    div.jx-image.jx-right img { right: unset !important; }
fixes it.

Re: Film simulations from scratch using Python

#26

Post by felixr »

LUTs are quite fun to play with. If you look for videos on "3D LUT Creator" you will find some cool things done using LUTs.

If you are looking for a great and free tool to create LUTs, have a look at https://grossgrade.com/en/ It is not easy to find IMO; I knew existed because I had used it and it took me ages to find it again...

Also, while I had no luck with 3D LUT Creator (trial) on wine, Grossgrade works fine :-)

Re: Film simulations from scratch using Python

#27

Post by [deleted] »

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.

[deleted]

Re: Film simulations from scratch using Python

#29

Post by ipsum2 »

Cullinet wrote: post #16
sldksk wrote: post #7

Pretty good, but that Velvia imitation looks a stop dark.

you'd expect to be a stop down because there's so little information to work on in the highest bits of digital (I don't remember gamma being applied which is instrumental to handle the log / lin perception / recording mismatch. But there's simply much less data in the highest ranges of digital unless you deliberately go about getting additional information. (ETTR expose to the right was the earliest widely adopted te…

Cullinet - if you had a blog talking about the technical aspects of photography/film, I would love to read it.

Re: Film simulations from scratch using Python

#30

Post by hatsunearu »

The thing about LUTs is that it's only mathematically valid if you know the type of data the "input" is--and I'm not just talking about oh is it an 8 bit image or a 12 bit image.

It needs to be aware of the color space and EOTF (an extended idea of "gamma")--which is why LUTs are only used in very controlled scenarios (e.g. for videography, the input color settings are fully detailed, for example Sony's slog, so the LUT is a reproducible, mathematically sound operation)

"RAW" photos from cameras are what we call linear color space, where the RGB values correspond linearly to the amount of light received by each photosite. If you try to use a LUT designed for RAW on an sRGB JPEG image, you're gonna have some problems, at least without screwing with the color space.

It's why I kind of gave up on trying to use LUTs in photo editing, it's just so unreliable.

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