Lighting a scene with Spotlights

Kev914

I watched the lighting video that you can access through the Daz Studio start up page. Afterwards, I added two spot lights to my scene. The one I put to the left of the figure and above. The other to the right. I looked through each light to make sure it was focused on my model. I had that Environment setting set to Scene only. In the preview, my scene looked OK. I did a test render but it was very dark. Not much light on the figure at all. I watched the video again, and I think I did what he did. But his scene was much lighter. So what am I doing wrong? (He didn't talk about what render settings he used. He mentioned that he would cover that in a different video.)

So why does my scene render so much different than the preview. I had to ramp up the light to 5000% before it came out looking like it did in the preview. In the video, he only had the it set to 100%. I didn't move the light or anything, just cranked up the setting.

I confess, that I didn't wait until the render finished. It doesn't start out dark and then get lighter as the render proceeds, does it? I guessing that it does not, as I completed the render at 5000% intensity and it looked nice. But in the preview it looked cartoonish.

Thanks.

mjc1016

If this is using Iray, then the default tonemapping settings are for a bright, sunny day...like the default HDRi that is loaded. 

Either you need to adjust the light settings (very high) or adjust the tonemapping settings...these are your exposure controls.

Also, the preview is a very general idea of things...not anywhere close to what the final render will look like, so that 'toonish' look, is 'correct' (at least at those intensity levels with the default tonemapping).

Kev914

Thanks, mjc1016. When I reset the spotlight to 100% and adjusted the tone mapping slightly, it rendered pretty much like it appeared in the preview mode. I was going to try to adjust the shadow, but I the Shadow was greyed out. There were no parameters to adjust it. Is there someplace you have to turn it on. I am getting shadows in two directions probably because there are two lights. I was going to try to set it so the shadows only came from one direction.

Thanks again.

mjc1016

Can you adjust the shadows from lights in the real world? 

Nope...

So you can't do that in Iray, either.  That's what it means by a physics based photorealistic renderer.  It follows the laws of physics, as closely as a computer simulation can...

That said, you can turn Iray into a sort of physics based, biased renderer, by swapping over from Photorealistic to Interactive and get the shadow controls back.

Kev914

Thanks. What you said makes perfect sense. I had it in my head to adjust the shadows, since that was what I saw in the tutorial I watched. Now I understand why the shadow options aren't available. Thanks again.

mjc1016

I'm not on a machine with Iray, so I can't give exact instructions...but if you change the light to a shape (rectangle or disk are best for this) and increase its size you will soften the shadows it does cast.

So if you take the spot with the offending shadow and make a disk with a size of 1 m or more, the shadows it casts will be, naturally, much softer.  What you are doing is creating the equivalent of a studio softbox or large diffuser (using photographic terms).