Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] General Discussion => Topic started by: indexofrefraction on 2018-05-08, 09:04:30

Title: colormapping 16bit (antialiasing / brightness range)
Post by: indexofrefraction on 2018-05-08, 09:04:30
hi there...

in vray i use reinhard colormapping and i save my pix as 16bit images to have some space for post edits
now in corona i noticed that my lights are totally burnt in, darkening in post does not allow
to reduce the white halo of a lights surrounding for example, while this works perfectly in vray.

in corony the lights generally seem to be much brighter in the output due to the missing colormapping.
this results in much stronger antialiasing artefacts and also limits post editing a lot...

how do you guys cope with that?
best, index
Title: Re: colormapping 16bit (antialiasing / brightness range)
Post by: HVB on 2018-05-08, 09:44:15
Have you tried high light compression on your camera?
Title: Re: colormapping 16bit (antialiasing / brightness range)
Post by: indexofrefraction on 2018-05-08, 13:40:05
Have you tried high light compression on your camera?

yes but if i use values > 1 the whole image gets darker (which i dont want)

Title: Re: colormapping 16bit (antialiasing / brightness range)
Post by: iacdxb on 2018-05-08, 17:34:25
Have you tried high light compression on your camera?

yes but if i use values > 1 the whole image gets darker (which i dont want)

In Corona Camera Tag, I hope "Use Photographic exposure" is unchecked, increase "Exposure (EV)" numbers.
If checked, use shutter speed and F-stop setting.

...
Title: Re: colormapping 16bit (antialiasing / brightness range)
Post by: indexofrefraction on 2018-05-11, 09:55:51
In Corona Camera Tag, I hope "Use Photographic exposure" is unchecked, increase "Exposure (EV)" numbers.
If checked, use shutter speed and F-stop setting.

hm? this seems unrelated to colormapping.

anyway,
using highlight clamping in the rendersettings (frame buffer settings) seems to do the job!
Title: Re: colormapping 16bit (antialiasing / brightness range)
Post by: maru on 2018-05-11, 13:26:13
using highlight clamping in the rendersettings (frame buffer settings) seems to do the job!
Just remember that it will clip the dynamic range of the whole image for you. (so with low enough values there will be no difference between a sun and a light bulb ;) )
Title: Re: colormapping 16bit (antialiasing / brightness range)
Post by: indexofrefraction on 2018-05-11, 23:59:40
yes but how would you otherwise fix the antialiasing problems on visible lights?
(without post working on 32bit files)

also the documentation is very brief on both highlight compression
what is the algorithm behind this?