"light" noise at 1500 passes

Hey Guys,

I keep getting these white speckles in my scene. I thought if I rendered 1500 passes it should be enough to get rid of any noise but this noise seems different :


Does anyone know what I’m doing wrong here or do I simply need more passes?

Sofa by Karigar and table by Nikitron (blendswap)


Are those lights behind glass? That is a really bad idea with a path-tracing renderer. You really should be using some kind of photon-tracing algorithm for that, or at least bidirectional path tracing (although that only helps so much)

You mean the lamps on the wall? That’s the translucent material within cycles. Maybe I can try make that diffuse and see what is does.
Will get back to you on that!

Thanks for the reply.


There’s negativa’s tutorial on this. See node setup for lights there

These artifacts are called fireflies or (with digital cams) hot pixels, they are a common artifact in path-tracers. Removing them is usually done in some post-process, google will help you when searching for these terms.
One way to deal with them is to render at double resolution, then use a tool such as “remove speckles” in photoshop or something like that and then downsample to the target resolution.

Thanks for the replies.

I decided to try and render a similar scene with Yafaray. So far i don’t see the artifacts showing up.
When I get home tonight I might try to change the translucent material to a diffuse material and render again with cycles. I’ll get back to you with the results :slight_smile: