Vray Lens Effects Glare causing Colored Noise

[davision]

I am getting strange multi-colored grainy noise when I use the Glare effect. Bloom is fine.

It doesn't seem to always happen and I haven't tested enough to find the cause.

Does anyone know how to prevent this? It looks really bad.

[davision]

I've attached an image snippet so you can see the problem -- this is the Glare element and you can see the noise all over the sky -- although it's elsewhere too.

[grantwarwick]

Temporarily. turn on the intensity mask and set it to .5 or something.

[svetlozar.draganov]

I am getting strange multi-colored grainy noise when I use the Glare effect. Bloom is fine.

It doesn't seem to always happen and I haven't tested enough to find the cause.

Does anyone know how to prevent this? It looks really bad.

Would it be possible to provide a scene for this issue ?

[davision]

The mask intensity doesn't help Grant. It seems to eliminate the star pattern of the glare (what I actually want) but the noise is still there.

I've attached a 2014 file. There are some bright lights (render them with the day exposure camera) and some dimmer lights (use the night exposure cam). Both produce colored noise but the night cam (rendering either night or day lights) is far more noticeable.

I will also send this file directly to your email, Svetlozar.

[svetlozar.draganov]

Thank you very much for the provided scene.
The issue with the noise from the Lens Effects is related to the exposure setup of the scene.
I did a few quick test renders and I realized that something is wrong with the exposure cause I changed the background to color 1,1,1 and it looked way too over-brighten than it should be.



This exposure makes the unnoticeable noise with values even less than 0.001 extremely visible.
In order to solve that issue you have to change the exposure settings to more appropriate values.

In the following example I have changed to Shutter Speed to 80 and the light intensity is increased to 5 - as you can see the background now matches to specified color in the environment tab and the noise is the Lens Effects is gone.

[davision]

I know I'm using a high exposure setting but I thought the Vray Physical camera is supposed to imitate a real world camera. The settings I'm using are very much in line with what you would use to do night time exterior photography.

And night time photography is one place you'd definitely expect to see glare.

[svetlozar.draganov]

Well it seams that you are right - the exposure settings are appropriate for the Night Shots.
Lens Effects behaves properly with daylight-exposures but it seams that there is something wrong with night ones at least for Glare option, Bloom seams to act normal.
I'll send the case to our developers for investigation and I'll let you know when we have some news about it.

[davision]

Thank you.