I am trying to render a transparent PNG for a website with a dark background.
When I render the image with the transparent film in Cycles, it produces a lot of noise at the edges of the gradient (shown on a black for clarity)
The material is a Principled BSDF shader with emission and alpha falloff controlled by ColoRamp:
The issue is in the alpha channel. You can see it clearly if you switch to alpha channel in render window, and toggle between Evee and Cycles render slots. Evee's alpha does not have this pixelation effect:
I tried bumping the sample count to 300, but that did not fix the problem
Here is the scene blend file: