What is the main difference between the Rokinon 85 f/1.4 and the Nikon 50mm f/1.4?

I mean, other than the zoom length and the auto focus. What is the main difference?

The Nikon is higher quality glass
Rokinon is more a generic lens

if you want quality, get Nikon

The doctor is correct.

Also what you may want to know is that neither of those lenses are zoom lenses. They are what are called "prime lenses" or having a single focal length.

Unless the lens says "AF" (auto-focus), then they are probably manual focus lenses.

And finally, a 85 mm lens is longer than a 50 mm lens

Here is how you can tell what the angle of view can be seen by different focal length lenses.

http://imaging.nikon.com/...simulator/

Main difference is quality. The Rokinon 85f1.4 is made by Samyang of Korea and marketed under several names, Rokinon being one of several. I bought the Samyang 14f2.8 to see what all the fuss was about and while it does have good IQ it can be a pain to focus in bright sunlight hence I'm now waiting for a Sony 5'' LED screen. Its a good lens but its taken a back seat to my Canon 16-35f2.8L II and my newly rediscovered Canon 15f2.8fisheye. I don't mind auto focusing for landscapes but would baulk, with my eyes anyway, at trying to do it for portraits. For that I get good service from the very fast auto focusing Canon 85f1.8. I also have a razor sharp copy of the Sigma 50f1.4 which besides the Samyang are the only 2 lenses I have that are not made by Canon. If you're not happy with the Nikon 50f1.4 and you get the opportunity, have a look at the Sigma.