Gamma Question

[kwerch]

Damn! I really thought I was onto something-

 

I read Sawyer's Post on the Chaos Forum about his take on Gamma correction-

 

http://www.chaosgroup.com/forum/phpBB2/viewtopic.php?t=15364

 

I tried to post this there but was told that I needed special access- Looks like alot of the same folks here so here goes-

 

His take was to enable gamma correction in the configure drop down-

 

I checked the display and set that at 1.8

 

On the bitmap Gamma input I set it to 1.8

output I set to 1

 

Things were looking alot better- Less of a haze-

 

I did have the gamma correction turned on and the Vray framwe buffer open-

 

I adjusted the levesl in the Frame buffer very similar to the suggested curve that I have been reading about and things were looking pretty good-(to me anyhow)

 

I was feeling pretty good about things until I went to open this image in PS.

The levels applied in the Frame Buffer were not saved-

 

I went back and disabled the "enable gamma correction" and I am back to an overdark image but I can save any corrections I do in the frame buffer-

 

I have to admit , I am getting a little frustrated with this- But I think I need to get a grip on this-

 

Answers or directions appreciated-

 

karl

[Christopher Nichols]

If you save your image as an HDR or EXR format and open it in photoshop, the monitor curve will work. If you save it as an 8bit image, you will not get the correction when you open it in photoshop.

[kwerch]

Any problem with saving as TGA? Hdr does not open in PS and EXR is not an extension that I can save in-

TGA seems to work-

[Christopher Nichols]

HDR open with Photoshop cs2. TGA do not save floating point unclamped colors. Since you are not using HDRI or EXR float and using a low bit TGA, use Solution 1 in Sawyers doc

[Sawyer]

 

I checked the display and set that at 1.8

 

On the bitmap Gamma input I set it to 1.8

output I set to 1

 

karl

 

I am not sure why you have this set to 1.8. Shouldn't that be 2.2?

[kwerch]

Believe me- I am trying to set things up in the Gamma world as you have outlined but my results are "sub optimal"

 

I just did a quick test after reading Christopher's post and I get an awful result-

 

I think there are other settings involved that I am unaware of at this stage in my experimentation-

 

so I am back to my 1.8 setup and linear mapping-

 

here are my settings and result-

 

I can render with the settings as you suggest 2.2-1-.454 and post the results if you think you can see something there that might help explain this-

 

I also saved this image directly from the vray frame buffer as tga- with the color corrections applied-

 

Wanted to say Sawyer that your efforts on the explanation on the chaos forum were helpful- I don't exactly get it but SOME of the dots are connected at least-

 

karl