Noisy material

[jow]

Im trying to make simple glossy black material but keep getting noise problems-

This is just straight diffuse and no refection. HSV= 0,0,5
Here's the same, but grey, HSV= 0,0,70


Spotlights in the scene have no area shadows, Area lights have subs of 40, tried upto 100 and still there
GI Ir map high preset, HSph. subdivs, 80 LC defaultish.
AA Adaptive QMC, 1.4
Any one got any idea how to fix this???
EDIT
And im using LWF, maybe this is the prob....
Cheers

[Morbid Angel]

you need to lower your qmc sampler noise threshold

[jow]

Cheers Dmitry, Dam didnt even think to try that!!, i'll remember for next time.....
I found that pushing the Vray light's subs to 200 (ouch) fixed it. So rendered scene with subs at 40, then re-rendered the just the problem area at 200 subs as a region render. Then comp'ed over the top, quick fix i know but a deadline was looming...
BTW, changing the Vray light to Skylight portal also fixed it but i got poor GI that way.
Anyway thanks again..

[jow]

Just tested it, had to go all the way to 0.001 on the subs, had all ready dropped it from 0.01 to 0.005 (Version 1.49.61)

Didnt think a drop this low would be needed due to the re-worked QMC, anyway thanks for the pointer

[Morbid Angel]

hmm this is odd. What size is your light? - the light size will determine the amount of samples needed, if your light is too large then it will produce more noise.

[jow]

2 lights @530x400mm so not very big at all....

[jow]

Fixed it! due to the windows having rails, the lights where over-lapping these rails, changing it so there are 2 lights per window and not over-lapping the rails solved the problem with out the need for high subs/ low noise threshold
Cheers dude.

[Morbid Angel]

Well then this explains it, while the frame was near the light thus making the light extremely close to the frame which has produced the noise, here I have made an example:
Grid is moved further away from the wall, and closer to the light source, the shadow disperces and becomes not visible, but it is still there in a matter of noise which you got

[jow]

Nice one Dmitry, thanks for the example