Re: Laowa/Rokinon/Samyang build quality?
I have the same Samyang 7.5 fisheye for m43 and it seems to be very well built.
The only "issue" I have is that my copy seems to be different than what I see others saying - on mine, infinity is exactly at the infinity mark. Every recommendation I have seen about the lens says that you need to back away from the infinity mark somewhat, but if I do that even slightly, I get blurry shots. At the infinity mark I get excellent shots. So I have no leeway. But perhaps I shouldn't! I mean, in a perfect world wouldn't infinity be at the infinity mark?!? One could argue that they have done some quality control at the factory and started properly adjusting their lenses. Damned if I know.
As far as 15mm, I don't consider that all that wide. I mean, I greatly prefer the P12-35 lens (and similar O12-40 and new P12-60) over a standard kit lens because I find 12mm much more useful than 14 (forgetting about the better IQ with the more expensive lenses). So 15mm is not going to do much for me. I do use the O17mm 1.8 lens a lot, but that is for a different use - more a general purpose lens. 15mm seems neither fish nor fowl to me. Just MHO, of course.
Rich
Olympus E-M10; Panasonic GM5
m4/3 lenses: Oly 75-300; Oly 14-42 f3.5-5.6 II R; Oly 17 f1.8; Oly 40-150 f4.0-5.6 R; Oly WCON-P01 adapter; Rokinon f7.5 fisheye; Sigma 19 f2.8; Pan 20 f1.7; Pan 12-35 f2.8; Pan 12-32