Hey! I have a little problem. I’ve been rendering hair and some of it has got a wierd look. Could you help me out and tell what is this and how to fix it? Thank you!
I think, this might be an anti-aliasing issue. But how to fix it, any suggestions? 
I’ve seen this before, and I can’t exactly remember what I do to fix it. Possibly it’s a child style thing, (curl, braid) maybe the period is too high and the amplitude too low. Or maybe it’s a anisotropic shader issue. Can you post a simplified blend?
Thank you for agreeing to help! I did, indeed, use both braid and anisotropic shader. Do you think, you could have a look and see, what is possibly the problem? 
simplified.blend (2.73 MB)
You were absolutely right! Anisotropic shader was the cause 
I’ve replaced it with Hair BSDF shader and it worked. Thank you a lot for advice!
Yeah, I think the anisotropic is exaggerating the issue, but you can definitely use anisotropic in hair. Just took a quick peak, there’s a few areas that can speed things up, for one you are using very high steps at 10. You really don’t need much beyond 6, those are exponential whihc is why you bvh is through the roof. Also you have curl children on with an amplitude of 0, which is won’t do anything and may cause issues…
thank you for the responce! I am using curl for children for the sake of flatness property. It makes hair little more… mmm… smoothed and flatted, though I can dial it down a smith. I 10 steps for strands only for the viewport, for rendering I use 6, but do you think that viewport steps are also taxing on the memory?
Thank you again for you advice! You really helped me. I was trying to dig something out on anti-aliasing and was getting desperate and it turns out it was not really a problem
It’s funny, I’m not seeing those bands when I look on my machine. Now you didn’t pack any images (there’s only one, an hdr) and it makes me think that that hdr image is causing the problem, and you have masked it by removing the only glossy shader in there. Try opening the original file you sent, and removing the hdri and just use rgb white, does the banding still happen, if that fixes it, then you should use a different hdri.
oki… i will try to do that. I also read once somewhere, that wierd things might happen with strands, when strand width is smaller than the size of pixel. If the resolution of your screen is different, than you might not have the problem.
That could be it.