Excessive Noise o

[indigooo]

Hello there, i just got Corona Renderer and I trully amazed, specially with the lightmix, awesome.
Problem is that since I am migrating from Vray, I find myself in a situacion where I get way too much noise, and got some questions about lightning:

1)What's the best way to adjust lights? Correct intensity in rollout parameters, or increasing/decreasing intensity in the lightmix setup
2)HDRI Lightning, it's generating way too much noise in my opinion, it's normal?
3)I get like 100 times more noise when the lights in the lamps are inside it, and light bounces from the interior. It's normal? Setting the light in the bottom of the lamp reduces the noise by a LOT. Example below, first image, 1 minute render time lights inside the lamps, second image, lights (disk type) at the bottom of the lamp, 1 minute render time.
Also i get a lot of noise from the wall using a light material, simple spline extruded 0.1mm acting as a LED strip.
My render settings are the ones in the image (using the new light solver gives me a little more noise)
Render time on all images is 1 minute. threadripper 1950x

[TomG]

A lot of topics about noise are covered in the helpdesk articles, e.g.

https://coronarenderer.freshdesk.com/support/solutions/articles/5000501983-how-to-get-rid-of-excessive-noise-

- Best way to adjust lights, no real best way, depends on your intent. Significantly increasing the intensity of a light source in the LightMix will introduce noise, and best then to use the >Scene and re-render (but using LightMix is still a fine way to experiment with intensities). Also, don't forget to enable denoising for LightSelects, if using denoising. Keep in mind any lights not assigned to an actual LightSelect and left in the Rest (unassigned) won't be denoised.

- If using LightMix, is it assigned to one of the LightSelects? Are portals being used to help?

- Bouncing lights from inside a light surface will introduce noise, yes, as it's a more complex calculation. You can try lowering the MSI; alternatively, you can use rayswitch so the lamp material doesn't bounce light (something black in the GI slot)

- Complex shapes with a LightMaterial will always take longer to clean up; the polycount will also play a part (less significant than the shape complexity). Depending on the scenario, you can use Emit Light off on the complex shape, and a simpler shape with Emit Line on (with the simple shape being invisible to the camera).

- 1 minute really is not long to run an image like this one with lots of light bouncing :)

- And using Denoising is a good thing; don't know if it was used here (would still need longer than 1 minute though)

[indigooo]

Thanks for the response, and I am indeed using denoising on final results yes. And light mix is being used on the lights, all of them, and yes using lightportals on the two apertures.
I found that setting the window's cristals to non "thin" and giving them a low IOR value reduced the noise a lot.
Gona try to tasselate the LED mesh and see the results, and thanks for the tip on the rayswitch on the lamps, anyway lowered the light position and is much nicer now.
And 1 minute was enough, giving it 5 minutes was showing similar noise patterns, it was just a "raw" example of the problem, anyway, thanks a lot for the help.

[TomG]

Window glass set to thin is also a very good idea yes :) Should always be the case where refraction isn't actually playing any noticeable role (so, almost all windows!)