Summary: I never thought I'd want to go wider than 24mm but after seeing the photos on the Flickr Samyang 14mm f2.8 page (The lens is badged under different names, including also Bower and Vivitar.), and particularly those of the night sky with stars, I decided to give it a try.
Summary: I purchased this lens for night photography, and when I received it, it would not fit on my Sony A7R. I removed my 35MM Sony Lens very easily, and then tried for several minutes to line up the mounting ring on the Rokinon Lens, and it simply did not fit.
Summary: The lens is very good and substantially what I wanted. I was disappointed to learn than with my Alpha 330, the lens can only be used in the manual mode. This is not a huge problem, but i was under the impression that it would be fully integrated with my Sony.
Summary: What a little gem! It's all that the other reviewers say it is. The only things I can add are: 1) buy PTLens software to remove the lens aberrations. PTLens works either as a stand alone or can plug into Paint Shop Pro x5 & x6 (and presumable Photoshop).
Summary: Bought this lens to get that super-wide perspective on APC-sized sensor camera (Sony A35). I'm using this lens primarily for landscape, starscape, and indoors. First impressions: 1. This lens is sharp, easily sharper than the Minolta primes and all the Sony zooms I owned.