lighting challnege

[bpzen]

Flat mesh lights are better, and larger is better unless you really need sharp shadows. .

When you say large, after i create an emitter using the script form lights = 500% 1000% any recommendations or trail and error?

Teh bigger i make these the more it blows up teh room light seems to go on for ever and bounce all over again making rooms way too bright - setting distribution way low seems to help allot here

[mlru]

this is a physically correct renderer, so your light objects must reflect that.
scale a square so it resembles the size approximately of the actual light source (or use the actual mesh if it hasn't too much polygons).
use physically correct emitter settings, i.e. realistic efficiency (usually 0.25 should be max), power in watts 25, 50, 75 etc, correct color temperature.
distribution is the overall "importance" of the light, and should be set to 1 if all other settings are correct.

if the image is too bright or too dark with these settings, adjust your camera, not the lights (as you would in real life)

[dsyee]

Also, how did it take 5 hours for you to get 6000 samples/pixel? Your hardware is better than mine...

I lost one of my cards so im working with 1 Titan at the moment until i upgrade my PS, I also am using SSS on skin and hair and there is another figure in the scene but not in the camera view that's probably the length of time issue im have.

My scene had SSS (glossy/diffuse mix) on skin and hair, as well, plus diffuse transmission in the clothing, so that's probably not the issue. You only really need to keep off-camera objects in the scene if they're going to contribute noticeably to global illumination (walls, ceilings, large distinctly-colored objects, etc.). Off-screen figures are really bad imo - they usually add a ton of texture and geometry for no visual effect.

For mesh light size yes, I'd just experiment with the scale. FYI, smaller meshes create sharper shadows.

Like miru said, there isn't a reason for a scene overall to be "too bright" or "too dark," because you can adjust the camera exposure settings. The brightness of your lights can affect the contrast between light and dark areas, but if the entire scene is too bright or dark, the exposure settings (ISO, F-stop, and Exposure) can take care of that. If you don't have any background in photography, this might be a useful primer: http://photo.net/learn/basic-photo-tips ... -exposure/

[bpzen]

thanks for the link dsyee, I also had PMC set on teh kernal, perhaps that was addign to length of time.

I cut the render in half time wise (5000 samples in about 2 hours now) by changing lights (removing ISE fill lights) and going path tracing.

yes 80% of my issues im sure is little to no photography bacak ground. I am addressing that with some courses but that link helps

im getting better results with the advice here, much better. I think my main problem was IES filters and too many ISE lights in general. I had 6 ceiling lights with IES filters in the room thinking they would act like house ceiling lights and be fill lighting, but they just caused all sorts of noise it seems

I went to a set up like you showed and its crystal clear.

As far as size, i get the sharper shadow part for sure, teh highlights on characters seem to go away if I use smaller lights unless i put the emitter directly in front of the character. so i tend to use larger emitters 500% - 1000% original size to get those highlights light catching eyes and lips etc...

Anyway this has all been extremely helpful. thank you all for the tips