I have noticed that when I render a Poser character in Vue 7.5 with the characters hand touching or near the body, in certain positions the fingertips create a glow effect on the body (like a negative shadow). The effect (shown in the attached picture) depends on the orientation of the character with respect to the camera (and possibly lights). However, the effect is not dependent on a single light; I have deleted the three lights (Main, Directional, and a Quad Spot) separately and none of them is the sole cause of the problem. In certain orientations the effect disappears in others it is quite strong. This effect is not limited to the fingers but occurs whenever a body part is close to another body part. Is this a bug? Is it specific to Poser characters? Or is there something wrong with my lighting setup? The attached images were rendered using User Settings (default values) and using Global Radiosity. If anyone has any advice on how to avoid this effect I would be happy to hear it. Thanks, Isaac

That's a phenomenon known as light leak. That happens with radiosity. I'm not sure if you can call it a bug, it's a secondary effect of the radiosity engine in Vue. It's not directly related with your lighting. It's not related with Poser characters either, it can happen with anything.

There are several things that influence this effect. From the top of my mind, here's some:
a) if your characters have some self luminosity, even if small, this effect increases. SkinVue applies a certain luminosity to skin, for example, to fake SSS.
b) if you have very thin objects, like planes, that also increases the effect.
c) if you have radiosity gain, it also increases

I'm sure there are more, but I can't remember now.

Some ways to decrease it, other than counter-acting the effects above, again from top of mind, not an exaustive list:

1. increase your advanced effects setting in the render settings
2. if 100% is not enough, edit these effects and apply custom radiosity photon map. Decrease the maximum gathering radius, increase number of photons, etc.

Hope that helps.

Oh, of course, one radical way of getting rid of it is by not using the GR lighting model. :-)
Instead, you could use GI and use secondary lights to simulate the light bouncing that GR automatically does.

This mostly happens with lighter colours, like here the skin. As our AOM (congratulations, Artur!) said, it only happens with GR, and it hppens with GR when "optimize for outdoor rendering" is on. Untick this box, and the effect should disappear, unless there is some luminosity in your  materials.

I can't say HOW long I've searched for the hidden 'under-the-skirt' light in this image:
www.renderosity.com/mod/gallery/index.php

Thank you all for that information.

Thanks, Bruno. :-)

Yes, I forgot about that checkbox. I don't normally fiddle with it since most my renders are outdoor (and renders are considerably  slower with that unticked).

Thanks for the replies guys. Optimise for Outdoor Lighting was already unchecked. In Advanced Material Editor: Effects Tab; I found Luminous set at 0%, however Ambient was set at 40%

I set Ambient down to 0% for both torso skin and hand skin and the result is much better.
(see attached image)
You will notice that the effect is not completely gone; there is still some glow around the thumb and the little finger. I wonder if there is another variable somewhere that adds Ambient or Luminous light?

Thanks again for your help; this is one step further towards solving this problem.

Try reducing the radiosity gain or alternatively, use Rutra's suggestion and use the GI lighting model

Thanks dburdick, that has helped a lot; I set Radiosity Gain to 0.00 and the glow is essentially gone (see attached image). I have one question about what the radiosity gain does though. If the value is set to zero, does that mean that there is no Radiosity effect at all? If so is there any value in using GR with the gain set to zero? (ok, that's two questions ;) )

Radiosity gain zero does not mean there's no radiosity. If you want to test it, do this: apply a solid color to the surface near the hand and see that the fingers become slightly tinted near the surface, with that same color, from photons bouncing from that surface to the hand.
The radiosity gain simply enhances this effect.