This is a compositing nodegroup that replicates lens abberations in post processing.
see a quick test of the lens node here:
In the film industry lens abberations indicate complex camera lenses, hence a big production budget.
This is the reason why CGI makes heavy use of Lensflares. Since John Knoll's lightfactory the usual and fast way to produce them digitally is by defining a point in the image that shines with a given brightness.
Based on this point the whole effect is created.
The downside of such an approach is that the point doesn't produce the whole area, that actually is bright in the image. Especially big bright areas cannot be represented by one point, neither in position nor in shape.
Therefor the lens compositor node uses the emission and glossy renderpass as input, using every pixel in the rendered image as sources to create complex and vivid lens abberations.
A complex nodegroup with efficient calculation lets you define the intensities of the different lens phenomena:
- streak color & streak
the last parameter is quality which simply downscales the calculation to a smaller resolution. with lower quality the calculation gets slightly faster and phenomena get blurry.
The node is meant for VFX work, Motion Design and huge spaceships with lots of bright windows and engines flying through space approaching even bigger stars...