Author Topic: Corona Sky still too blown out and faded  (Read 824 times)

2022-12-13, 18:00:38

lupaz

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I know that the sky had a lot of development in the last couple of years, but I still feel it has the same problem as usual: It completely goes to white on a huge area around the sun location. It just doesn't look realistic anymore now that cell phone cameras got so much better.
Below I have a very simple scene with a sun/sky at defaults, and some geometry blocking the sun. As you can see the grey of the walls (default corona physical material grey) looks ok, but then the sky looks completely white, and the areas that do have some color look very desaturated.

Is there any way to reduce the glare of the sun to just the circle of it and leave the rest as blue sky like in the photo on the top right?

Thanks.

Using 3Ds max 2023 and Corona 9.1

Note: highlight compression doesn't seem to help
« Last Edit: 2022-12-13, 18:04:26 by lupaz »

2022-12-13, 18:09:30
Reply #1

lupaz

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Here there's one with the sun much higher, but the sky looks dull in my opinion.

2022-12-13, 18:53:56
Reply #2

Aram Avetisyan

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Hi,

The sky is brighter and more white towards the sun direction. You can check the very opposite side of the sky from sun and see that you have the "right" blues there.
And remember that you can change sky turbidity, custom color correct it, and do Tone mapping to get the look you want.
The sky model cannot guarantee a perfect match for any taste. You should play around with all available tools to get the result you want.
Maybe other sky models can give the result you are up to faster.
Aram Avetisyan | chaos-corona.com
Chaos Corona Support Representative | contact us

2022-12-13, 19:00:34
Reply #3

lupaz

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Thanks.
The photo I attached on the first post is pointing towards the sun. You see it behind the tree. The area around it isn't white. My feeling is that in Corona, not sure why, the whiteness around the sun is extremely big compared to reality and photography.

I understand that there are ways to tweak it, but maybe the default sky could come more "user friendly" by default. Just an idea.

You could move this post to feature request probably.

Thanks.

2022-12-14, 03:05:13
Reply #4

DPS

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Thanks.
The photo I attached on the first post is pointing towards the sun.


Is that definitely the sun, or a cloud? I've found the sky model to be pretty close to photos that I've taken - attached are some raws as they appear by default in ACR. Perhaps in cool climates the halo is a bit smaller? New Zealand in winter vs Australia in summer.

Specs: AMD 1950X, Aorus Gaming 7 x399, 64GB RAM, 1080ti. Win10, Max 2017, Corona 1.7.3

2022-12-14, 03:11:09
Reply #5

lupaz

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Thanks.
The photo I attached on the first post is pointing towards the sun.


Is that definitely the sun, or a cloud?

It's The sun. I purposely took the shot before posting here.

Look at the 3rd of your photos. There's a clear gradient. I don't think I can get that results with corona sky.

 How much of those photos is pure white?

2022-12-14, 09:37:15
Reply #6

DPS

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Thoughts on this? Here's that photo again but without any built in make-it-look-nice profile from Canon (I opened it in RawDigger). This is closer to the VFB output.

If you added one of the Kim Amland LUTs to your frame buffer then you'd be closer to comparing apples with apples. I think those LUTs are derived from a Canon profile.
Specs: AMD 1950X, Aorus Gaming 7 x399, 64GB RAM, 1080ti. Win10, Max 2017, Corona 1.7.3

2022-12-14, 09:41:31
Reply #7

maru

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Check out this thread, and especially this Juraj's post: https://forum.corona-renderer.com/index.php?topic=38361.msg205701#msg205701

Also please note that:
- Corona Sky is based on real-world data collected in Prague. Sky+Sunlight looks different in different places around the globe.
- The appearance of sky greatly depends on tone mapping / post processing (just changing white balance will affect it A LOT).
Marcin Miodek | chaos-corona.com
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2022-12-14, 14:15:32
Reply #8

lupaz

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Thank you both. I'll continue experimenting....

Appreciate it!