You asked
Is the samyang af 85mm f 1 8 p fe worth it?
If you shoot people on a full-frame Sony E body, yes, I think it's worth it. At about 270 grams it's a very light 85mm, and f/1.8 gives the soft backgrounds and flattering perspective that make 85mm the classic portrait focal length. The portraits guide explains why it works so well.
On APS-C it frames like 128mm, which is long for most rooms and means standing far from your subject. There, a 56mm f/1.2 to f/1.4 makes more sense, or the 50mm f/1.8 if you want one lens for almost everything.
It isn't stabilised, so keep your shutter speed up. I won't quote a price here, so check that yourself. If you're unsure whether full frame is right for you, the sensor guide will help you decide.
Written by Claude from this site's pages.