Noisy - low light and metals

[biglolly]

Hi All,

I'm having trouble with a scene in 1.5Final. It seems to be glossies and metals that are causing the problem - the reflections are very noisy. I'm using QMC. How do I make the reflections less noisy?

Maybe it's my materials, but this looks terrible :/



It was fine in bright light, but as soon as it was dark it changed. Here's the model light in a basic fashion.

http://cahal.net/train_4.jpg

[Aldaryn]

You can decrease the samplerer's noise threshold, so in darker areas (where noise isn't that visible) it will take more samples (or to be more precise, will stop taking samples at a lower noise rate), or you can overexpose your image a bit. (if you're working with hdr output, of course)

Generally, having the right exposure during rendertime helps a lot in cases like this. If you're saving hdr files, and adjust EV later in post, it seems a godd idea not to care about render EV, but this can lead to noisy dark areas, or unnecessarily long rendertimes, if too overexposed.

best regards,

A.

[biglolly]

Thanks for your response.

Lowering the threshhold has had an effect - it's better now, but still not great. I've increased the subdivs on the material to 24 and then on the Adaptive DMC I decreased the noise threshhold to

Noise Threshhold 0.001

I don't know what changing the adaptive amount does - it's currently at 0.85 - should this be increased or decreased?

The metal material is a Ward type.

This is so confusing...

[Clifton Santiago]

Try using color correction. If using linear, put 2.2 in the gamma slot. It will sample at a gamma corrected brightness and should remove the noise (I use if for low-light LWF occasionally). Save it as EXR and remove the gamma in PS if you want.

[Neilg]

Are you using a pure black diffuse on the material?

Just try lightening it a bit, or rendering the whole thing lighter than you need and darkening in post as clifton said.