The image looks grainy

[Tanya_00]

Hello!
I don't know what happened with my Corona or 3ds max settings, but the renders take much longer  and they look quite grainy.
I changed denoising to "Corona High quality" however there is not that much difference. When I start rendering I don't receive any messages that the file is too large. I'd really appreciate your help. Thank you!

[GeorgeK]

Hello!
I don't know what happened with my Corona or 3ds max settings, but the renders take much longer  and they look quite grainy.
I changed denoising to "Corona High quality" however there is not that much difference. When I start rendering I don't receive any messages that the file is too large. I'd really appreciate your help. Thank you!

Please provide image examples and also clarify which Corona version you are currently using.

Thank you.

[Tanya_00]

Hi George,
Corona version 4. Image provided.

[maru]

The first thing I would recommend is resetting all render settings to their defaults (Render Setup > Scene > Reset settings).

[Tanya_00]

Thank you Maru

[Tanya_00]

Hi Maru,
I reset the Corona settings as per your advice, however the image still looks quite grainy.
Please find attached for your reference. It has been rendering for 1 hour.
Do you have any suggestions? Thank you!

[djstevanovic]

Well, for production render use noise limit 2, for test images up to 5-6 and i prefer to use corona high quality denoiser at 0.65.

You stopped render at noise % ?

[maru]

My advice:

1) Upgrade to Corona 5 if possible - I don't see any reason to use Corona 4 anyway - https://corona-renderer.com/download
2) Make sure you have portals in your scene - https://coronarenderer.freshdesk.com/support/solutions/articles/5000501660
3) If the above steps do not help, find out whether the noise stays in direct or indirect lighting and adjust the relevant render settings - https://coronarenderer.freshdesk.com/support/solutions/articles/5000516731

[GeorgeK]

Hi Maru,
I reset the Corona settings as per your advice, however the image still looks quite grainy.
Please find attached for your reference. It has been rendering for 1 hour.
Do you have any suggestions? Thank you!

Hi Tanya,

As suggested from our ticket conversation, I would highly advise against using both "light-emitting" light material and Corona light on top of each other, either disable the light emission of your lightmtl or remove it altogether and use the CoronaLight to be visible and as your main light emitter.

Lastly in the scene you provided for us, Legacy Medium resolving is activated on your configuration settings don't know if that's something intended. To disable it go to System Tab, enable devel/debug mode, then navigate to Performance tab > Development/Experimental and disable the use of legacy medium resolving. Without it enabled you will get better render times and less noise at the same amount of rendering time.

[Tanya_00]

Hi Marcin, George,

Thanks for your replies. I will make the changes.
Can you please send a screenshot showing where I can disable legacy settings?  I can't find it.

[Tanya_00]

Well, for production render use noise limit 2, for test images up to 5-6 and i prefer to use corona high quality denoiser at 0.65.

You stopped render at noise % ?

Thanks for the tip!  Where do you find the noise % data? Thank you!

[Tanya_00]

3) If the above steps do not help, find out whether the noise stays in direct or indirect lighting and adjust the relevant render settings - https://coronarenderer.freshdesk.com/support/solutions/articles/5000516731

Hi Marcin,
I've downloaded Corona 5 and added a portal material. It still takes a while to render. I've added CESSENTIAL_Direct and CESSENTIAL_Indirect, but don't see them in Corona VFB.

[Tanya_00]

Well, for production render use noise limit 2, for test images up to 5-6 and i prefer to use corona high quality denoiser at 0.65.

You stopped render at noise % ?

Thanks for the tip!  Where do you find the noise % data? Thank you!

Apologies, found the stats for noise%.

[GeorgeK]

Hi Marcin, George,

Thanks for your replies. I will make the changes.
Can you please send a screenshot showing where I can disable legacy settings?  I can't find it.

Open render settings (F10) go to System Tab, enable devel/debug mode, then navigate to Performance tab > Development/Experimental and disable the use of legacy medium resolving. Let me know if you require any further guidance.

[Tanya_00]

thank you George