Killing the speckles!

[tclancey]

I know this has been covered many many times, but I have a small project where I’m fighting the perfect storm. I have a dingy scene including emitters, rough surfaces and reflective surfaces. Some surfaces are rough and reflective, yay!

Clamping has become rather crucial and sensitive, I can clamp to a good reflective look but get too many speckles, I can clamp to get rid of the speckles and loose all reflection. I played with the deionisation and I’ve got to a level where I’m losing the detail I can live with.

I’ve tried setting emitters very low and placing lamps, I’ve tried replacing lamps with emitters, I just can’t find a setting that looks right without ramping the render passes up to nuts levels. This is an animation so I can’t afford to do that.

I’m know I’m asking for the holy grail here, and the real answer is to push up the render, but I just can’t.

Does anyone have any advice for low light scenes, any tutorials on gloomy lighting?

Many thanks.

[SterlingRoth]

Replacing emitters with lamps is a good start, Cheating the size of those emitters is a good way to reduce the noise. Just make the lamps bigger to increase the likelihood of a ray hitting them.

See if you can add some other lamps to fill in dark areas to add some leeway to your scene clamping.

There are also some node tricks to cut a light out at a certain distance or ray depth:

using the above tricks, I was able to reduce fireflies a fair bit in my quicky test scene:
original:

refined:

There are definitely tradebacks, and it will take some fiddling to get it to match exactly, but it’s a bit better.

Here is the .blend for a closer look at what I did: light optimization.blend (785.4 KB)

[dbalex]

Or you could use neatvideo in your postpro