what's up with exr, color adaptation etc = burnouts

[lukx]

How on earth Bertrand and others who are using "don't affect colors adaptation only" on, are able to avoid burnouts.
Here's some rough render with Reinhard color mapping :


and "don't affect colors adaptation only" exr output opened in photoshop :

[lukx]

also notice with exr and color adaptation only , lack of shadows (behind tv)

[super gnu]

is it not possible to fix this by using a lower external light intensity, and/ or reducing the reflectivity of those surfaces? im not sure if there is something simple like a button youre missing. if you start building the scene with "dont affect colour, adaptation only" turned on (as i usually have) then you just light and texture the scene to avoid burnouts. i dont know if you have other lights in the scene, but it looks to me like youre asking the external light to do too much. in a real scene it might well be darker in the foreground (the result youd obviously get if you reduce the light intensity) then you can just use levels in ps to bring up the darker areas? saving as exr you have all that nice colour range to play with after all.

[super gnu]

no idea regarding the missing shadows though ..

[lukx]

hmmm I guess I will have to try this. So far I tried playing with hdr toning in PS but it's horrible.

[chrisjacks21]

Lukx, interesting point. I used to always tick 'dont affect colors', but of recent I have been leaving off and using reinhard to reduce burn, I find it really lets you get more natural light in without burnouts albeit at the expense of sampling/noise issues. Interestingly, whilst Bertrand seems to get such great results with it on, P.Guthrie gets equally as excellent results with it off using Reinhard (pretty sure he menioned this on his blog).

[lukx]

yeah, regarding the noise I also noticed more problem with it when "dont affect col" on. But this missing shadows is boggling my mind now. Hope Bertrand will show up can shed some light on this topic.

[rivoli]

I guess don't affect colours it's really meant to be used with a proper linear workflof, where you output to exr and the only colour correction you do is gamma 2,2 in linear mapping. this way the render will look exactly as you see it in the vray fb with "display colours in srgb space" checked (well, almost exactly that is..). with any other colour mapping and/or correction you won't get consistent results, as the reinhard colour mapping won't be stored into the saved exr.

anyway, I usually don't use reinhard myself. what I started doing to avoid burnouts and retain decent contrast in lfw renderings, is darkening materials. it goes for reflection colours/values as well.. but I guess whatever does the job is as good, and sure reinhard colour correction is a good method to achieve pleasant and realistic light distribution.

[BBB3]

I wish I could help but I'm not quite sure why I'm not getting these burnouts. But I think Super Gnu hits the nail on the head. If you do everything (modelling, shading, test renders) using the same setup, i.e. with "don't affect colors adaptation only" and sRGB on, as I do, you will naturally light your scene and adjust your materials so that they don't produce burnouts. Then again, there are situations where burnouts are unavoidable and indeed correct, photographically speaking, especially if you rely on external sources alone to light a rather dark interior and you have pretty bright materials close to the light source. For instance, as I believe I wrote somewhere else earlier, my whites are actually closer to grey and the RGB values for other solid colours are pretty dark too, which may explain the lack of burnouts.
As for the absent shadows, I'm pretty sure they are there, but the second image is a lot brighter overall (look at the bottom of the bookshelves), wich may make your shadows look fainter. If you output to 32 bits and lower the exposure in PS, I'm pretty sure they would show up again.

[flino2004]

I think, changing to "don't affect colors adaptation only" is changing the intensity of the color that you have on the reflection parameters so what you see there is the white background.

[dlparisi]

What kind of tone/curve mapping are you doing in photoshop? What's your Reinhard burn value? I never understood how well photoshop handles >1 values though for 32bit files since the curve editor, etc max out at a value of 1.

[lukx]

reinhard was at 0.4 for bright. the exr version I posted didn't have any tone/curve applied. Basically with EXR there'a only HDR Toning available , Exposure and levels. No way to apply curves.

[dlparisi]

reinhard was at 0.4 for bright. the exr version I posted didn't have any tone/curve applied. Basically with EXR there'a only HDR Toning available , Exposure and levels. No way to apply curves.

Totally forgot PS can't do curves in 32bit! Other than exposure do any of the other tools push the +1 values back into the <1 range. Without that I don't think there's any way to match the reinhard output since it's affecting all of the values, trying to keep the +1 values back in normal range. I think your only option is to lower the camera exposure and then push the image levels in photoshop (perhaps using levels?.) just a guess though.

[BBB3]

Magic Bullet Photolooks allows lots of tweaking, including curves, in 32bits straight in PS (or as standalone).

[lukx]

but bullet can't open exr and when saving 32 tiff , standalone still won't open it. I can't use photolooks filter (this works) because it's not working properly with wacom tablet (I'm not using mouse anymore).
So maybe I'm just missing something how to open exr in MB