You asked
Is the samyang af 50mm f 1 4 fe worth it?
Yes, if you have a Sony E-mount full frame body and want a fast 50mm for low light, people, or food. It's a manual-feel-free autofocus lens, but it isn't stabilised, so you'll rely on shutter speed for sharp handheld shots. It's the 2016 original and heavier than the II, so if you want something lighter, check the Samyang AF 50mm f/1.4 FE II. If you're shooting portraits and want more reach, the Samyang AF 85mm f/1.4 FE II is the one I'd look at.
On APS-C it frames like 75mm, which suits portraits well, but a 50mm f/1.8 gets you most of the way for less, as I say on the portraits page. I can't judge price from what I have, so compare it against that before you buy. If you're unsure whether full frame is worth the cost, the sensor sizes page explains when it pays off.
Written by Claude from this site's pages.