Looks great, but when I run a render, the shadow from hair strands comes out as sort of blotchy circles.

Any thoughts how to fix it?  The shadows for the spot, which is reflected back is set to:

Raytrace
Blur Radius = 5
Samples = 40
Min Bias = 0.8

Really just tagging on to see a more definitive answer here...

But I usually go with min bias on lights at 0.2... based on other posts I've read.

Blur radius looks quite high for finer shadows maybe... would be my other suggestion?

Have you tried less blur radius?

What are you using in terms of render settings? e.g. what min shading rate? Irradiance cache?

Render settings (1/50/50/10/0.1/32):

Min Shading Rate is 0.1
Irradiance cache is 50

I decreased blur radius to 1 with no real effect, last night.  Also tried min bias at 0.6...no real effect.  I have not tried down to 0.2 though.  I'll give it a whirl.

MSR

What is the reason for putting MSR at 0.1 ???

The minumum default is 0.2.

You CAN go below MSR 0.2, but you will have to lower it for each and every object, in your scene in all their own parameters palettes too..........

Check in the manual around page 397 (PoserPro2012 manual) for full info.
Sorry, do not know the page for Poser9 manual by head.

Did you have SSS enabled?
Put the hair and the face in a different SSS group.

Min bias for the light 0.2 to 0.5.
Blurr radius at 5-10

is Smoothing enalbled on something?

SSS is enabled, and it may be the cause.  I just turned off shadows for everything but the rim light coming from left as you look at the pic, and still get this effect, as seen in the pic.

I am going to have to see how I put them in different groups.  That does not strike me as something that I know how to do offhand.

I did not turn on smoothing for anything, so if its on, its on by default.  Smooth Polygons is checked in my render settings though.

OK, best I could find re:Groups was to check in EZSkin v2, Editor tab, and the Hair is set to "Ignore"...so I guess I am not using SSS on the hair prop (it is a prop, not a figure)

You set the SSS groups in the SSS nodes.

Figure face & body in one group1
Figure eyes in group2 ( I Put innermouth also here in group2)
Hair in group 3

I turned off the reflecting light and its still there.

This is got to be something very obvious I am missing

What happens if you untick the "light emitter" option for the hair prop?

Or, alternately, the "cast shadows" option?

Here's a quick render using the default render settings with IDL light rig. The reflector is located to the top left and the RimLightL and BG Left lights turned on, no SSS. The camera was located to my taste, of course. Like I said, it gives a certain look, sometimes desirable, sometimes not.

I wonder if the blotchiness has something to do with what was being discussed here: Post about Light Emitters

EDIT: if skin does not look quite same, its due to a new skin I tried, to see if it was releated.

Attached Link: http://www.renderosity.com/mod/gallery/index.php?image_id=2351455&user_id=117649&np&np

Using emitters kinda means letting go of traditional specular and using reflection (fresnel_blend) instead. That's why your skin looks so dry. If you use EZskin, you enable fresnel and set it in a careful balance with your emitter distance to target and its ambient value. It's not a science yet but can yield spectacular results.

Mixing some spots with an emitter is a possibility but it's easy to blow it out (yellow bloom) with too many light sources.

This is with 2 emitters:

I have no idea how big the reflector(s) of Colm's IDL rig are, but I remember from my own tests, that having a big reflector (or big emitter obj's in general) with a lower intensity gives better results (in terms of "blotches"), than having small emitters with high intensity.

Based on Richardson's reply (thanks!) I ticked the Fresnel, and see what you mean about it being not so dry.  (one on right is Fresnel added)  That does hit the render time though...  :(

I am gonna roll the whole render, and see how it looks.

Thanks for the tips!

Thanks for the help all, and Kudos to Snarlygribbly and Colm.  I highly recommend that light rig!  First time using it, and other than shading problem above...you can get a really nice render via point-n-click!

Here is the finished render, click for bigger, then click again for biggest!

Quote - Thanks for the help all, and Kudos to Snarlygribbly and Colm.  I highly recommend that light rig!  First time using it, and other than shading problem above...you can get a really nice render via point-n-click!

Here is the finished render, click for bigger, then click again for biggest!

Wait, how did you fix it again? You fixed it by buying that Light Rig?

What was the actual problem that caused those spots in the first place?

See this discussion on emitters/size/shadows from Bagginsbill:  http://forum.runtimedna.com/showthread.php?63342-Light-Emitting-Objects&p=627644&viewfull=1#post627644

My guess was that it was related.  In any case...what I did was add a spotlight to the light rig, parented to the reflector, aiming the same as the IDL, at a low intensity, enough to drown out some of the blotchiness, but also enough to add fine shadows.

In my experience, you can always get rid of IDL blotchiness by increasing the IDL samples.

Quote - See this discussion on emitters/size/shadows from Bagginsbill:  http://forum.runtimedna.com/showthread.php?63342-Light-Emitting-Objects&p=627644&viewfull=1#post627644

My guess was that it was related.  In any case...what I did was add a spotlight to the light rig, parented to the reflector, aiming the same as the IDL, at a low intensity, enough to drown out some of the blotchiness, but also enough to add fine shadows.

Do you agree this is a problem with poser pro 2012?

Quote - In my experience, you can always get rid of IDL blotchiness by increasing the IDL samples.

I tried that but still got the blotches. I could try again though :)

I use Poser 9.  I can't say it is a problem or not...it was very easy to workaround for me.  I suppose you could raise sampliing, etc...but I did not want to sacrifice render time.

I'm assuming people know you can set IDL samples WAY higher than the sliders in the D3D dialogue permits. Bounces too.

It's quite possible to use fairly small emitters and ramp up the samples, tinkering with the irradience sample size and bounces to get better results. This comes at an inevitable render-time cost and doesn't always combine well with regular lights.

Can be worth a try though.