GAMMA 2.2 problem

[chortik]

Hi,

 

I render usually exteriors of plannings and buildings and I use max2008 and vray. I have a problem with Gamma correction, I followed the Aversis tutorial and and built up a sample scene but some things have gone seriously wrong and I do not know how do go forward.

 

Most of my bitmap textures I used before appear too bright and I have to reduce their brightness in Photoshop so much that they seem almost black in Photoshop.

 

In case I need to change some simple color parameters my color selector has almost only the bright values of any color, so adjusting darker tones is almost impossible.

 

Most of my renderings come out bit too bright and really flat in means of brightness and contrast.

 

So if anyone could help me or direct me to proper tutorial I would be grateful.

 

Best regards,

C.

[Tim Nelson]

Well, you need to make sure that you have your input gamma set to 2.2. That way when you load new bitmaps they won't be all bright & washed out.

 

If you have an existing scene with bitmaps in it already, you'll need to merge all the objects into a new scene. At that time, all of your pre-existing maps will then be adjusted to your 2.2 gamma.

[chortik]

Hi Tim,

 

Thank you for answering my question! I override gamma 2.2 with all bitmaps I use in my scene when I apply them to my materials. In material editor everything looks fine, but when I render the scene then all bitmaps are still much too bright.

 

C.

[mangalore]

is because you are applying gamma correction twice. Use linear color map with gamma 1.8 or 1.0 in the situation when your texture appear overly bright

[chortik]

Hi mangalore,

 

Can you explain it bit more closer, where I do my fatal mistake? Maybe you can add a printscreen or something...

 

Regards,

 

C.

[Tim Nelson]

Oh, maybe you are using the Max frame buffer when you should be using the Vray frame buffer. If you use the Max buffer you will get double gamma corrected and will look terrible.

[chortik]

Hi Tim,

 

I am useing vray frame buffer, so...

[greyowl]

The thing that messed me up with textures looking too bright was the import bitmap choice I had selected. Once you set your max gamma setting to 2.2 as well as the input and output gamma in max preferences you need to make sure your bitmaps when brought in through the material editor are set to use the system default gamma or manually set to 2.2 on the override. If they are set to use the images own gamma they will likely look too bright. Ideally you want them to show up in max relatively close to how they would appear in photoshop so you can have a predictable base to start working with.

Edited July 10, 2010 by greyowl

[elliottsmith]

Hi Chortik,

 

It looks like you have resolved your problem but if you need any more info on gamma, I have just written a few articels for my work. There are a few parts to it, all relating to different workflows.

 

http://www.jigsaw3d.com/articles/linear-workflow-and-gamma-correction

 

Hope they help.

[Rafael Reis]

I think you appied gamma twice

[stormchaser]

i prefer to use color correction map instead of applying gama to bitmap while importing, there are more interesting settings, and i dont use the color correct map that comes with max, i use cuneytozdas' color correct map.