ies lights sphere or disk

[artmaknev]

I'm working on this scene, mostly lit by interior lighting, I wanted to use IES lights but was getting a ton of noise. 

Then I tried to use sphere shape instead of disk and like a miracle most of the noise cleared up really fast!

I thought we were supposed to use disk for IES lights, or did I read something wrong?

[Ondra]

I can take a look later if you send me the (simplified) scene

[maru]

Stupid question just to make sure: your disc lights are facing the right direction?

[artmaknev]

ondra - thanks, will send scene a bit later

maru - direction is correct, the ies profile is pointing down, I tried about 5 different ies lights, same issue (switching to sphere shape fixed it)