Tom Savage

I'm currently working on an experimental raytracer which is currently presenting me with a strange artifact that I can't explain.

If you look at the first attached file, you will see an example render (1 sample per pixel). On the right-hand side, there is a noisy band in line with the light source (red sphere). I've added arrows to point out the noisier areas.

When I increase the number of samples - the noise is averaged out and disappears, but has a blurring effect (visible in the second attached image).

Moving the light source will move the artifact as well. It always appears in line with it, moving across the x axis

Has anyone seen this sort of effect before?