Sun control in blendigo.

Announcements, requests and support regarding the Blender Indigo export script
Woodie
Posts: 188
Joined: Thu Oct 11, 2007 2:25 am

Post by Woodie » Thu Jul 03, 2008 8:34 am

Looks lie this is actually indigo problem:

http://www.indigorenderer.com/joomla/fo ... php?t=4499

I did not wanted to have a night scene but more like dusk or sunset. I did put it under horizon to strengthen the results. Problem is that sun is probably to bright. I don't know even at dusk (when it is a bit dark) I should see effects of strong lights.
I actually (just a second before) took a photo with above settings (ISO 100, f8 1/500s), nice sunny weather (3PM) and it is around 1 to 1.5 steps underexposed. The rendering I got looks like 1 to 1.5 steps overexposured. Maybe camera tone mapping is incorrectly calibrated?

PS: I took photos with Sony A700 and according to some tests ( http://81.115.30.35/wnu/img/TF_A700.jpg ) actual sensitivity at ISO100 is 120. That makes the difference even bigger.

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Kram1032
Posts: 6649
Joined: Tue Jan 23, 2007 3:55 am
Location: Austria near Vienna

Post by Kram1032 » Thu Jul 03, 2008 9:06 am

The sun&sky system isn't perfectly correct. The extremer you get the less accurate it is, with it's optimal settings at (I guess) sun pointing straight down (noon) and turbidity 2.

Just tonemapping properly should fix it. You can lower tonemapping by 1.5 steps (if you use Camera-Tonemapping, exactly, if you use linear or reinhard, at least roughly), by for example lowering the (reinhard) postpro value by 1.5...

Oh, I forgot: Reinhard generally avoids pure black and white and tries to get a balanced, often due to that flat looking, image. For special light situations like this, using camera-tonemapping will be far better, I'm pretty sure...

Woodie
Posts: 188
Joined: Thu Oct 11, 2007 2:25 am

Post by Woodie » Thu Jul 03, 2008 9:27 am

You see problem is that using Camera Tone mapping will not solve anything because brightness aspect ration sun/lights is incorrect from the beginning. I would have to use much brighter (more powerful) lights than they really are, and it is even more difficult with photometric lights (where you do not have control of light power). Camera tone mapping (and any other tone mapping) will change the brightness of the scene not just sun.

Woodie
Posts: 188
Joined: Thu Oct 11, 2007 2:25 am

Post by Woodie » Fri Jul 04, 2008 4:49 am

Pibuz,

I looked again at your thread:

http://www.indigorenderer.com/joomla/fo ... c&start=30

What was your light setup?

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