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Lights

Posted: Wed Feb 09, 2011 12:22 pm
by BurnGamer
Hi everyone,

I want to add some nighttime lighting to my scenes and I followed the tutorial on the website, but I still have some problems.

I made a small 2'' x 2'' square on the ceiling as you can see in the first image. I then created a new material and applied the "100W incandescent" material to it (colored in yellow).

I rendered the scene with the Reinhard and obtained the second image.

Then, I rendered the scene with the Reinhard method again but I set the power of the light to 25W instead of 100W (third image). As you can see, both images are nearly identical, even if the light has a different power. Why?

I then redid the renders but this time with the Camera method. The fourth image is with a 100W light the fifth one is with a 25W light. There's a small difference, but they are very dark compared to the others.

Is there a way to set the lights correctly and obtain a clear image like the ones rendered with the Reinhard method?

Re: Lights

Posted: Wed Feb 09, 2011 2:45 pm
by compadrelucas
Are you trying to make a comparison between two diff. power lights?
Reinhard is suposed to be an automatic exposure option, that's probably why there is not much diff. in the first set of pictures.

Are you using the same camera settings for both 100w and 25w?

Re: Lights

Posted: Wed Feb 09, 2011 2:50 pm
by StompinTom
Jack up the exposure for Camera tonemapping (decrease shutterspeed, use a lower f-stop, increase your ISO).

Reinhard will give you the exact same output because there are no other lights in the scene to judge by. It takes the brightest pixel and uses that as a reference for tonemapping, so if there's only one light, it won't matter how bright it is. That's why it's great for a foolproof exposure.

Camera tonemapping gives you more control over exposure.

Re: Lights

Posted: Wed Feb 09, 2011 3:44 pm
by BurnGamer
@compadrelucas @StompinTom

I didn't know that Reinhard would make no difference no matter the intensity of the light. I guess I know now!

I was using the same settings for both lights. According to what you said StompinTom, my camera settings were not optimal. My ISO was to low, my shutterspeed and f-stop were too high.

I rendered a similar image again and it's way better! Thanks to both of you!