Using 2D image operations is a fast and powerful way to adjust and combine your rendered images.
At first work in Compositing during the Alpha cycle will be directed towards adjusting lighting without having to rerender. This tutorial will briefly explain how this is currently done, and what to expect in the Alpha Cycle
V12.0's internal color format has been expanded to be able to save and load higher precision colors. In earlier versions the renderer used high precision colors for internal calculations but those colors were converted to 32bit images, or 8bits per component Red, Green, Blue, Alpha. Now the renderer's output is 16bits floats (called Half or Half Float format) per component. The new format provides higher color resolution and higher color dynamic range.
8bits of color resolution per component image only allows for 256 different levels of luminosity between black and white per component. The new format, with its 10 bits of color resolution, can store 1024 different levels of luminosity per component. And now, with High Dynamic Range, black and white doesn't mean much anymore.
The new format can represent any segment or 1024 levels of luminosity within the whole practical spectrum of luminosity going from very dark moonless night scenes to a white room directly illuminated by the sun at full noon. It is actually as if we used a 40bits per component image representation.
This new representation is especially important for rendered images because rendered images need to represent a much wider dynamic range of luminosity than what the traditional image format can allow. For instance, it is not uncommon to miss some details in shadowed areas of rendered images because they become completely black or to miss some details in a very brightly illuminated part of a rendered image because it become saturated to white. With the new format, all the details are preserved.
Here are some examples of how higher precision helps during compositing. You can brighten an image without getting banding. You could reduce an image contrast without getting flat dark grays and flat light grays. You can recover details hidden in dark shadowed areas or in brightly lit part of the image. Colors can also be stored brighter than monitor white so that colors that go above this are not lost and can be recovered in subsequent image operations.
Besides higher precision and higher dynamic range, V12 also brings the ability to support more than one buffer per image.
Color and alpha image data can be saved and loaded with our new Image Input/Output Plugins. A:M's new Image plugins can save and load from 8bits per component up to 32bits per component if the image file format supports it.
The OpenExr format (.exr) is one of the few formats that can save the higher precision data and multiple buffers, and is versatile enough to store any additional information that can help use its buffers without requiring explicit file format extensions. For this reason, the OpenEXR file format was chosen to support the additional functionality required by A:M Composite.