Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: lukaboskovic on 2020-05-31, 13:50:22

Title: create realistic sky with corona sky/sun
Post by: lukaboskovic on 2020-05-31, 13:50:22
After a years of use, i am still looking for the perfect combination of light system  for exterior...
Is it possible to get it with sun/sky ? What i mean by that is to get a really blue sky without post? Because by default and with right light the sky is allways extremly white, not blue.

I will post a reference image for that. (its also corona render from forum)

Title: Re: create realistic sky with corona sky/sun
Post by: sebastian___ on 2020-05-31, 15:21:00
In reality at least, it's a combination of factors. Like how underexposed is the image, where is the sun ? in front, or behind the camera ? Or using a polarizer filter (translation for a 3d render : use post processing or separate controls for sky).
  Even the lens size can be a contributor factor, like if the lens is very wide or tele. With very wide you can get a stronger gradient, from a bright blue to dark.
Title: Re: create realistic sky with corona sky/sun
Post by: agentdark45 on 2020-05-31, 15:33:50
A lot of photographers use graduated ND filters to essentially underexpose the sky to avoid the white burnout effect:

https://www.diyphotography.net/are-graduated-neutral-density-filters-really-useful/
https://photography.tutsplus.com/tutorials/quick-tip-replicate-a-graduated-neutral-density-filter-in-photoshop--photo-4888

As we have a lot more control, you could simply stick a BW gradient mask over a 32 bit exr of your image in photoshop, or even simulate it in the render scene. This would only lower the exposure, AFAIK ND filters use a polarizing film so I'm not sure what effect this will have compared to simple exposure reduction.
Title: Re: create realistic sky with corona sky/sun
Post by: Jadefox on 2020-06-01, 11:50:25
You can always try and have a color corrected corona sky in the background override.
Take the gamma down a bit and you will get a much darker blue sky without affecting the overall lighting conditions of the render.
Title: Re: create realistic sky with corona sky/sun
Post by: lukaboskovic on 2020-06-01, 20:24:18
Thanks all! i will try