Lecture 4 - Gamma Correction

If you use photoshop you will probably know about the 'levels' adjustment that is offered there. This allows you to make your photograph darker or lighter, in other words it adjusts the Gamma of the image. Gamma correction is built into products such as computers and televisions and it is set at 2.2. Mac computers are set to 1.8.

The Gamma setting is built in to compress the information produced in shadow areas (light and shade). The Mental Ray rendered used for Raytracing has to know the correct Gamma, otherwise rendering can take longer than it needs to. Also the with the correct Gamma the colour of bitmapped shapes is richer and more saturated. Gamma does not affect ordinary colour, only the colour of the bitmaps in your materials as they appear applied to geometry.

You therefore need to turn the Gamma on:

Turning Gamma on

Go to the customise drop down, and click on preferences > Tab - Gamma and LUT (look up table).

Check enable Gamma,

Also under bitmap files - Output and input 2.2

Enable Affect colour Sections

Affecct Material Editor.

Toggle the UI setting in the render panel to see preference box where you can change settings for test renders which will decrease render time.

Under Limit trace depth keep Max reflections at 2 and Max refractions at 4.