LWF Settings For Non-Baked Gamma

 Gamma Correction is calculated during render but is not baked in to the image. It is displayed with the sRGB button.

Gamma Correction is calculated during render but is not baked in to the image. It is displayed with the sRGB button.

I use Linear Workflow but I tend to not-bake gamma correction in the output. In Vray, by the use of sRGB button on VrayFrameBuffer (VFB), we can display the output in a gamma corrected way but can still have the image non-baked.

Why Not Baking The Gamma ?
A single image might be a mixture of:

  • 3D object

  • Lighting Passes

  • A matte painting

  • Photos

  • Masks

  • Live action footage

  • Additional effects

Not all of this is created by one person or station. Data can come from many sources.  The advantage of non-baked image is to allow the compositor to work on the raw image and apply the gamma curve by his own decision. By this way, the true 32bit values are stored in the image.

 Vray Render Settings For Non-Baked Output

Vray Render Settings For Non-Baked Output

What is 32bit Image?

In a jpeg image: The dynamic range is from 0 to 255.
0 is  the pure black and
255 is pure white.

This means :
White wall (properly lit) = value 255
Sun= value 255

Both the white object and the sun will have the same value on histogram. This is because of the limitation of a 8bit images which display the brightest white point as 255. Both whites get the same value on jpeg photo or a render.

 

However in real life, there is huge amount of brightness difference between a white shirt and sun. 32bit images-High Dynamic Range Images allow a higher range of brightness for different object. The images can be in HDR format or OpenEXR format (by Industrial Light and Magic)

In a 32bit high dynamic range image, there is a huge tonal difference between a white shirt and sun, although they look the same on the monitor.

You can check this on VFB by right clicking on  different points on the rendered image and reading the pixel values. You can notice that, areas which receive excessive amount of light (burnt areas) has a very high pixel value. ( using Linear Color Mapping)

The 32bit images allows :

  • Precision in calculations and color

  • Greater tonal range, (of highlights and shadows) like in real life.

  • Wider range of colors (visible on a high-end monitor) for color grading

  • Ability to work in detail on dynamic range

  • Ability to restore the original range after manipulating the histogram

  • True compatibility with wide gamut color spaces.