But look at my picture, the conditions are the same but my M4 is distinctly bluish and M3 renders normally, like yours.

 In the Material Room settings, both V4 and M4 were given a blue tint in the diffuse_map to the skin texture.  If you are concerned about this, change the diffuse color to white.

Thanks, that the solution. I've never really noticed in V4, but it drove me mad in M4. Can you tell me if there's an easy way to adjust the diffuse colour to all the map at one go, as I've had to do each part seperately.

That has always been a problem with no easy solution.  IIRC, there might be a script to make those isolated changes over selected object parts.  Currently, I use bagginsbill's VSSProp to enhance the skin textures of all my models.  The convenience, one change will carry over to all associated body parts.  Very easy to use once you get over the small learning curve, and you won't deal with unnecessary skin tinting unless you desire it.  Search the forum for VSS.  It is a shader system that make a world of difference.

Face-off did a script 2 years ago for V4 but it works on M4 as well.  Here it is (get rid of the txt extension).

What texture has a blue tint. I rendered the default , and the diffuse is white  ?  

It's the original texture that comes with M4 base.  I have noticed the blue tint in both M4 and V4; don't like it so I use the VSSPro to 'normalize' the texture.

My pic is m4 base - no blue in the material  ?   I dont remember making any changes ... another mystery I suppose

But there is a mat-pose file that loads a shader. This shader has a blue tint in the Diffuse_Color. The purpose is to remove some of the overall baked-in red of the color map, and then add red back selectively based on the lighting so as to make some semblance of sub-surface scattering in the skin. The redness is added using a Color_Ramp node driven by a Diffuse node to measure the amount of light hitting the surface.

This technique was introduced by me and then later discredited by me. But Daz has been using it ever since.

It works for many lighting situations, but not all, and the shader totally blows up if you're rendering with Poser Pro gamma correction turned on.

However, it isn't always blue - and sometimes it is too red. So it all depends on your lighting.

Since then, I've come up with better ways to render skin.

Here is a comparison, with my default lights, not Poser's default.

Left is plain no-shader M4. Middle is M4 with his Daz supplied shaders. Right is M4 with my free VSS shaders.

Which one do you think you should be using?

There is a bug with Poser Pro's (And maybe Poser 7's, too) P4 renderer.

After you open Poser and load your figure, render ONCE with Firefly and RAYTRACING in the MANUAL settings enabled.
You don't have to let the render finish, but it will unlock the P4 renderer's ability to render shaders correctly.

Except for effects based on actual raytracing, the "new" P4 render engine is as good as Firefly (and FASTER) in correctly displaying shaders.

But you first have to give it a poke by rendering once with FF.
Otherwise it will behave like the "old" P4 renderer and just tint M4's skin blue.
It will also render diffuse colors way darker than shown in the preview.
Again, this behaviour is gone once it is "unlocked" by a raytraced render.

If you close the scene and start a new one, you have to unlock the P4 renderer again.
If you open a saved "unlocked" scene fom a pz3 file, the P4 renderer stays unlocked.

As you can see, the "unlocked" P4 renderer shows no quality difference compared to the FireFly renderer but it is about 30% faster.

JoePublic - this is new to me. Thanks for the post. I never use the P4 renderer so I never ran into this. Nor have I read this posted before.

Thanks to all! I'll try to put into action what you've recommended.

Quote - JoePublic - this is new to me. Thanks for the post. I never use the P4 renderer so I never ran into this. Nor have I read this posted before.

but i remember months ago you showed someone how raytracing is important for AO and shadows and you made an example with P4 render . and it looked normal. 

I may test P4R occasionally because someone asks a question, but I don't fire it up and investigate it on my own, the way I do every little detail of Firefly.