Gamma value preset

The gamma value…

…is and has always been preset to 2,20 in the rhino render settings. With that preset all colors are completely overexposed and have very little contrast. Renderings with that setting are complete trash. Whenever I have to render something, the first thing I do is to set the gamma value to 1.

Can someone please explain to me why the preset value is 2,2? Do other programs use this value as well?

1 Like

Rendering internally is done in linear space. If you experience over exposure, this has nothing to do with gamma. For realistic results, I recommend not to change gamma to 1 but leave it at its default 2.2

This goes all the way back to 2004 when this issue was first mentioned on the Vray forum, by an expert render artist that worked for the film industry. I eventually wrote an article about it as well to better understand it myself. That article is however no longer online unfortunately.
Before we had gamma correction on renderings, rendered images would look dark and indirect illumination would have way too much color bleeding.

What it comes down to is that any image you see on your screen is gamma corrected. the standard for images on web is sRGB, and this color space is also gamma corrected to 2.2

During rendering, any textures you will use are converted back to linear gamma, since all calculations need to be done in linear space.



ha, it’s still retrievable:

1 Like

Thanks for the answer and the provided context.

Well, since I wrote the post, I have started with a new renderscene where I kept the default 2.2 value, although it looked wrong to me at first. I thought if everybody else uses it like that and no one seems to have an issue with it, I should try too.

What happened was that I simply used different intensity values for lights and/or environment maps to lighten the scene. Previously I was absolutely convinced that only with the gamma value set to 1, I was able to get good contrasty images with nice blacks. Though after trying the standard 2.2 gamma value and adapting lights and environment intensity values accordingly, I now think I can get results just as good and contrasty.

I guess I was just very used to starting with the gamma 1 value, so that changing to 2.2 simply looked unusual to me. After using 2.2 for a few weeks now, I have adapted to it.

This is very difficult to judge since there are so many variables involved. Even your monitor and its brightness setting plays a role here (as highlighted in the interesting, old thread you managed to dig out).

So for now I feel comfortable with the standard 2.2 and am less confused about it now. Now I’d like to withdraw my statment, from my start post:

I don’t think this holds up anymore.