Noisy renders

[nate]

Well, back with another problem!

I've attached an image of a render that I've been working on, the problem being how noisy it is. This is only a low res render but I'm getting the same results from the high res.

I'm using adaptive DMC (Min=1, Max=4, sampler thresh.)
Mitchell-Netravali anti-aliasing (0.333 for both)
Exponential colour mapping (Dark=1.0, bright=1.0, affect ticked)
Irradiance map set to low, subdivs=40, interp.=20 (have also tried Med with subdivs at 60 with little change)
Least squares and density based
Light cache set to 100 for low and 1000 for high res (scale=screen,number of passes=
DMC Sampler (adaptive=0.85, noise=0.005, min samples=8, global=2)

If there's anything obvious that I'm missing then feel free to call me an idiot, any ideas welcome

[nate]

yeh, that probably should have said number of passes=8

[vlado]

If you use V-Ray lights, you need to their subdivs.

Best regards,
Vlado

[nate]

Thanks Vlado, I doubled the subdivs on the Vray lights from 8 to 16 and it's made a big difference. Is there a reason why this occures on some renders but not others? I have had problems with blotchy walls before (even after changing over to least squares fit) would this be due to the light subdivs too?

Right, back to the drawing board - searching for the reason behind the light bleeds next, think this is my modelling tho

[instinct]

vray light's subdivs are pretty scene dependent of course. If a lightsource is far away from the shadow casting object then the penumbra shadow is rather small (=needs less samples). If it's really close the shadow gets very soft and needs more subdivs naturally.

Kind Regards,
Thorsten

[nate]

Cheers for that, will bear it in mind for future renders