[Manual Focus] Just recently bought this lens for shooting the night sky and I was very impress with the performance. Star Trails and Milky Photos turn up very nice. Vignetting appears to be non-existence.I was thinking between this lens and the 16mm Rokinon (Which also has great reviews) and for only $ more you get the 6mm drop in Focal Length for the 10mm Ultra Wide view. That to be me was the best extra $ you can spend to capture a huge range in a photo w/o getting the distortion of a fish lens (which an 8mm lens will get you).This is a manual lens, but for night photography it really isn't that big of a deal because you'll just leave the f-stop at 2.8 and focus at infinity for best performance.Lens is pretty big for it's size and it does not take lens filters. Given that lens filters are basically unnecessary in the digital world and that this isn't a walk around lens these drawbacks really didn't matter to me.$ for a solid prime ultra wide lens while a canon equivalent would go for $-$. Best bang for your buck.

[f/22] Super wide angle- 16mm equivalent. Easy to focus on stars.

[109.5°] This is my first wide angle lens. I can hardly believe how much of the scene fits into the frame. The lens is crystal clear and fairly easy to use. The manual focus and f-stop settings take some getting used to at least for me. Setting the focus seemed difficult at first,however setting the focus ring just before infinity puts almost all shots in total focus. Using live view with magnification puts focus dead on. The lens feels durable and well built. So far I have only taken shots to help me understand the lens but I am happy and impressed with it.

[Nikon F] All in all, I like the lens. The image is sharp even in the corners, and the F/2.8 is a plus. There is some barrel distortion, but at 10mm and this much glass, it is to be expected. I would be surprised if there wasn't any. You can play around with the various wide angle lens profiles in the 'Lens Correction' profiles in Photoshop until you get something close. Remember too, that this is a manual focus lens. At 10mm, it really isn't a big problem as the depth of field is very wide anyway. Another thing, before you pop the lens on the camera, READ the instructions for use. For instance, on my Pentax, I have to use the 'A' aperture setting with the lens or it doesn't work properly. Other cameras use different settings. I've included a picture I took for a client of a very narrow restaurant kitchen. It has been photo-shopped to remove some barrel distortion in the lens as you would any wide angle lens of this magnitude.

[109.5°] I just received my K-mount Rokinon 10mm and to my surprise it has aperture control. You can have the camera control the aperture or manual. I'm loving the quality of the lens, it's built like a tank.

[APS-C] Sony 6300 for real estate. Both my Sony 10x18 and Samyang 12mm leave huge halos or glowing windows. This lens is big, a 10mm built like a 135? But once you adjust and accept the size, the images are just spot on and almost no glow at the window edges.

[f/2.8] I purchased the Rokinon 10mm f2.8 lens for my Fujifilm XT-1 and XT-10 for landscape and cityscape purposes. I bought the lens because I was so happy with my Rokinon 8mm f2.8 fisheye I purchased two years ago. I didn't expect much from an inexpensive third party lens at first, but I was amazed at how sharp and contrasty this lens was. Its a manual focus lens, but the depth of field (DOF) is so deep, you barely need to even focus it unless your shooting very close up subjects. My respect for Rokinon products rose to a high level after the fisheye. With that in mind, I wanted an ultrawide lens giving me a wide field of view (FOV), but with out the fisheye effect for landscape shooting. The 10mm f2.0 with its 109.5 degree FOV sounded like the perfect lens for that purpose. It is very sharp, and it's very fast for a lens of this type. Its built well, the focus ring is smooth and firm allowing fine tune foccussing. Again, like the 8mm fisheye, the DOF is very deep meaning you barely need to worry about focussing all of the time as everything from a few feet to infinity is in focus, allowing you to compose and just shoot! The lens is fairly large and heavy, but compared to my older Zeiss glass from the film days, I barely notice it on either camera. I would recommend this lens to anyone seeking to buy an inexpensive ultra wide lens that still performs well. Since this purchase, I've purchased the Rokinon 85mm f1.4 for portrait work and look forward to trying it out. B&H, as usual, has good prices and ships very quickly. I live in Canada and B&H gets my purchases to me in perfect condition and in a very timely manner! Thanks B&H.

[1.71 lb] I tried some few night shots and it's sharp. The lens doesn't look cheap and plasticky, it's heavy and solid .

[109.5°] I'm a video maker and use it in gimbal for open takes. It gives me the expected result. The cost benefit is perfect.

[APS-C] I was a little wary about buying a manual focus lens mainly because I'm bad at focusing. It took some practice and using a lot of zooming in on live view with my D7200, but I'm impressed with this lens. The distortion on the edge is minimal and easily correctable in Lightroom or your preferred software. There's very little vignetting as well. I'll mainly use this lens for indoor photography but I think with practice it will make an excellent landscape lens as well. This lens seems a lot more sensitive to ISO and F stop settings than some others but that might be normal for such a wide angle. I'm still learning photography but I do not regret purchasing this lens and at this price I think it's an excellent buy.