Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] Feature Requests => [Max] Resolved Feature Requests => Topic started by: shiftman2012 on 2016-10-17, 08:17:17
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I would like to request Real Camera Response tonemapping operators in Corona.
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Which ones (tonemappers) do you have in mind ?
We tried filmic, but somehow it's not working as I hoped. The Reinhard could be improved by not washing out the blacks. So it would crisper, something like what F-Storm has.
Regarding camera response though, that can already be added as LUT. Works great.
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I mean HDR tone compressor responses for different camera types.
But for this is needed reinhard.
Arion , Octane, and many other GPU renders have this - camera response (it is how camera compresses raw image into low dynamic range- i think, different cameras do it differently).
Saddly but developers said that they will leave current reinhard untouched as it is, because they think whashed out look is more realistic.
And they believe this reinhard is correct .Maybe it is correct in interiors but exteriors look terribly bad. Highlight compression does not work on exteriors. They said that in blender reinhard is done exactly the same reinhard. Filmic works good. They said they willnot change because of a few people.
Current highlicght compress can be left untouched, but please add better reinhard with hdr tone compressor responses. It is not the same as LUTs.
I gues why so few people noticed issue that highlight compression has, whashes out image? It coud be better. I am disapointed that developers do not whant to add reinhard.
In exterior scenes current reinhard - does not work, i need to use filmic, o go to arion fx.
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well there is filmic now, which does not wash out the images. You can also load LUTs that emulate real cameras, several of those are included with Corona itself now
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I mean HDR tone compressor responses for different camera types.
You are confusing tonemappers with response curves. These are two different things, although in photography world, response & tone curve are interchangeable names. (in film, camera "responded" to light logarithmically, so hence the name "response", today chips capture linearly, so tonal curve is added to adjust tonality, hence "tone" curve, but it's the very same thing).
In CGI, tonemapper (nothing to do with tone curves above) only compresses highlights, it doesn't do anything else, it doesn't adjust contrast or colors. Neither do modern CMOS in digital cameras. They capture files linearly, add gamma 2.2 curve and then regular S-curve to mimic filmic behavior from times where film captured in Log.
F-Storm, Arion, Octane, all have some form of Reinhard. Even Reinhard and Filmic is basically the same, just how the curve (it's S-curve in logaritmic space) looks is done differently. Currently F-Storm has the nicest tonemapper, it's slightly crispier Reinhard, it doesn't wash out blacks, but the shoulder (highlight clipping) is similar to low Reinhard in Corona (it' something like 1.5-2.0 HC maximally)
The "response/tone curves" they additioanlly provide, stuff like Afgacolor_Futura_400 are film emulation curves. They don't compress tones from HDR to LDR. They are literally only curves, in LOG or gamma space depending on usage (film grading or general CGI), you could make them using curves in Photoshop by yourself if you wanted, there is no other magic there.
And you can use them as LUT currently in Corona. It gives the same behaviour as in Arion, Octane, F-Storm,etc.
Yes, I also would want better tonemapper, Corona Reinhard is really ugly and bland. And filmic is just weird somehow most of the time for some reason. But you totally can use camera response curves with LUT.
You can do what I do. Use low HC in Reinhard (like very low 1.75 for example), this preserves linear mid-section correctly, keeps good saturation and doesn't destroy blacks...completely. Then I use a little bit of filmic shadows for crisp blacks. And last, I use LUT to grade the overall tonality.
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Thank you for explanation. Thanks GOD ! i am not alone in this universe unsatisfied with current highlihgt compression reinhard version. i pray developers will hear our request
I vote for implementation of better reinhard - like F-Storm tonnemapper, as an addition to existing one. Is that posible? To see how it would work in real world scenario.
Tone compressor responses( raw compression responses) - i thought they are not same as LUT's. I do not understand all details, but i do whant to have this kind of feature that exists in Octane, Arion. Because now i have to save exr and go to ARION FX to do what i need. But i need to desaturate a bit.
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from f-storm tone mapping description:
Modern digital cameras have complex color processing to keep colors closer to real life. FStormRender tonemapping works almost like a modern digital camera. Yhis is what i mean.
Sorry, i was wrong. It is LUTs. Can you tell where to get all those luts? Do they come with a program and it can be copied?
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There is better person on this forum to ask this :- ) Search Dubcat's threads.
Generally you can get a lot of packages online, some free, some paid, only thing to take care is if they're in LogC space (made for video footage grading), or regular gamma space (bit more rate, as LUTs are mostly for cinema stuff). Corona LUT has "LogC" check-box, but I didn't try if it works fine, but I presume it does.
I think you can extract the LUTs from Arion even.
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thank you
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some LUTs now emulate specific cameras, so implemented