Quote -
Looks like specular or reflection (see my earlier posts in this thread, I mention exactly this problem in 2 posts) - make sure you have nothing in those channels for all the hair materials (you might have removed specular for the outer layers but not an inner layer, if they are different materials).

Which hair prop is this? I don't think I have it, but I'll try it if I have it.

This hair is a classic by Kozaburo called "Short Bob". You can get it for free from his website:
digitalbabes2.com/dload1.html

It was originally designed for V3, but using Hair Conversion System I got it to fit V4.

I've had a look at the mesh in Blender - the hair model is comprised of several layers of mesh. However, in Kerkythea, there is only one hair material. For an image of what my material editor settings are, please click www.tightbytes.com/images/Poser/Kerkythea/Settings.jpg .

As far as I can tell, I've got nothing entered in the specular or reflection areas except what was there by default. Perhaps those need changing or something? I'm so sorry to be such a thick newbie, but I'm really in the dark about things like Fresnel and Cosine and how or if they affect the render and my study of the material editor guide leaves too many holes in my understanding of this.

Also, I'm rendering using Photon Mapping and Final Gathering (SW), with ray tracing set to Extra pass 3x3... not sure if that plays a role.

Thanks so much for your patience!

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks