As you can see, the image shows my P4 render engine settings & the results. The areas that should be pure black are rendering with odd, bright & colorful artifacts.

I ran into a similar problem in my online webpage gallery with the gallery system I am using and posted about it on the gallery mod's homepage years ago. What was happenig with that - I would post an image in my gallery and if it had very dark areas that should be true black, it would display them in my gallery with these same kinds of artifacts on the black areas. When I posted for help all those years ago, someone explained it as the gallery mod on my webpage as having problems with areas that were 'blacker than black'. I know that doesn't seem to make sense, but, if white = 100 and black = 0, for some reason some black was registering as like a negative number.

I think that's what is happening with poser. For some reson, it wants to render those areas darker than a pure black and I end up with these artifacts. In the past when I have come up against these problems, I have adjusted my lighting a bit so that the shadows aren't as dark. But, for the scene I am working on, I need deep shadows =

I'm sorry if none of this makes sence, but I'd really like to know how to fix this. I've tried rendering in firefly as well, but my PC is a bit of a dinosaure & poser just keeps locking up.

The lights I used in this particular image are ones inclueded in the Genesis for V4 lightpack from Daz, but, I've had similar problems using the free RDNA dramatic shadows lighting too in the past.

Any help or suggestions would be GREATLY apprecieated. And again, I'm sorry if thise doesn't make sense, but it's difficult to explain when you don't know what's causing the problem and can't use technical terms.

Thanks!
 

PS - my apologise for the inital 3 postings of this topic, i had a cat-on-keyboard issue, lol.  He jumped up & pressed my space bar a couple of times while it was trying to post & 3 identical posts showed.  I think I have them deleted now though.  Ooops! 

It would be possible if the color math involved a programming error.  
If it subtracted the color values in ordinary signed form, without clipping
negatives, you could get bright colors for 'blacker than black'.  I've never
seen this in Poser, though......

Thanks for the reply Ockham.  I haven't seen this in Poser pre version 7.  

I didn't recieve any errors, everything rendered as usual.  Then when I saw the full render I noticed the artifacts. 

Do you have any idea how I might be able to resolve this?  It's very strange.

I think the programmers have sort of neglected the P4 renderer.  The last
time I asked a question to e-frontier about a problem with that renderer,
they answered more or less "Don't bother us with obsolete stuff."

Random possibility:
I notice you're rendering over a background shader.  There have been
a variety of problems with the background nodes.  What happens when
you transfer the background to a square instead?

Well, after some help from relik over at RDNA I have a much better understanding of this issue & know what was causing it... as you just said, p4 render engine lol.

Because my machine is pretty old I don't tend to use the firefly renderer too often as it just takes so long to render anything, but, after playing with some other light settings & the settings in the texture it's self, I'm satisfied that it is P4 R.E. causing the artifacts. So, I'm going to reboot & let firefly do it's thing, even if it takes all day lol.

Now, given that I've been farting around with this image for so long, it's obviously destined to look like absolute garbage =)  So I'm not actually expecting to post it anywhere lol.  I think it's just a rule of thumb for me - the longer i work on something, the worse it looks lol.

Oh well, we shall see.  Thanks for your help Ockham, very much apprecieate it! =D 

could you post the material for the wings?  i've definitely encountered this problem in firefly when i went out of bounds with certain settings.

Well, it's a cloak, not wings and it's from Roxana Vampire package at Daz.  It's the default texture on the cloak.  I won't post the image because, well, that would be unethical & a violation of terms of use/copyright/etc, but if you own it you should be able to view it =).

I was encountering the problem trying to render with the P4 render engine, rendering in firefly resolved the problem.