Interior scene - dark spots in darker areas

[jumping_jack]

hi guys, sorry for an annoying thread...until now i've been using vray mostly for the daylight scenes, now i'm working on an interior scene with only the interior lights in it and i have some issue with the render artefacts in the darker areas...

i have black spots/halos on the vaulted ceiling, i increased the quality of the irradiance map from -3/-1 to 0/2 but the spots become only smaller but even more visible, i tried to adjust the light cache in any possible way too (subdivs 2000, sample size 0,01, filter size 0,01) but without any result

which setting should i adjust to achieve a smooth gradient change between the darker and the lighter parts of the vault without that dark/light splotchy pattern?

i have also a curiosity, in the third image - that is a screenshot taken during the LC calculation phase - there are clearly visible hexagonal multi color samples under the LC noise, is there any way to change their size or they're a default setting without any possibility to be changed?

thank you

vray 1.48.89

[broomstick]

These problems occur with low light and low samples in the Irradiance Map.

Try changing values of the camera exposure, and the use different values in:

hsph subdivis and samples

Normally values of 50/20 will work for external and a lot of light

Interior rendering want values like:

60/40

64/50

This is because the samples take the duty to render details: if the samples value is too small, the renderer looks to find detail where there is none, so you get the splotches.

Raising the samples value, usually gets rid of them

[jumping_jack]

thank you very much! i increased the sample value to 50 in the irradiance map menu and everything is fine now, i left all the settings on my usual values so the render time is still fast, with the 0/2 IM rate or the 3000 subdivs in LC the render time was too long