[CS-mount] Tack sharp and lots of fun! Great Lens!

[f/1.2] Just received this on 4/11 for my K3 and glad I didn't wait as B&H is already out of stock a day later! All exaggeration aside, my preliminary day and night shots are fantastic. Vignetting is acceptable at wide open, but stopping to f/7 quickly erases this. I see very minimal, if any, CA across the aperture range. Samyang's UMC and NCS are no gimmick. The bokeh is nice and soft. I still need to put this lens through a full day of shooting, but for now this is a serious bargain and worth every dollar, hence the preliminary 5 star rating. Best of all, this is a rectilinear lens, not a fisheye! There is no heavy pincushion distortion on the borders. Landscapers like me appreciate power poles and buildings that do not bend on the periphery of the image or need post-processing to correct. I didn't expect this to have an aperture ring, but for the Pentax you simply turn this ring to A (auto) and have full electronic aperture control from the camera. The manual focus ring has just enough resistance, but if you're clumsy you could certainly bump this out of focus. I do wish infinity focus was a hard stop, but this is nitpicking as most lenses are the same. The protective lens cover/cap is a bit flimsy, but does stay in place. However, I wonder how well this cover would remain intact if the lens fell just 3 feet? For those who complain this lens needs AF to be worth the price (there's always someone), they need to ask themselves why that truly matters for a prime UWA lens in the first place. Since this lens conveniently went out of stock soon after I purchased it, I added a photo of the item to prove I own it and to add credibility to this review. I am not a Samyang employee, but I do appreciate QUALITY third party lenses and not having to pay premium prices for the Canikons. Samyang really stepped up their game with their 14mm prime, and IMHO they've elevated the bar again with this 10mm.

[2.3 oz / 65 g] Good lens...

[2.8 to 10mm] Well built, sharp as a tack...just a little bulky.


However, the lens is take your breath away sharp and is a wonderful addition

[2.3 oz / 65 g] This is quite a nice lens. Even when wide open the image is really sharp in the centre. The colours are neutral. The build quality is excellent. The focusing feels better then my Sigma 30mm art.

[0.205 lb] I got one of the first copies of this lens in Pentax K mount from B&H and I have to confess I am using it as a shift lens on my Olympus m43 cameras with a Kipon shift adapter. In terms of sharpness, this lens beats easily whatever else is out there for m43, including the Olympus 9-18mm and the Panasonic 7-14mm. No color fringing or distortion noticable. It's a little on the heavy side, and I am not sure whether I trust the focusing mechanics. I am always very gentle when using it. But in terms of shear optical performance, this lens is a gem.

[2.8 to 10mm] Wonderful glass for a landscape survey. Good, strong and very light lens for very little money. He demonstrates minimum chromatic aberrations and very interesting colour picture. A virtual presence is felt on the lens of polarization filter. Possesses very moderate distortion in the class, that interesting in an artistic plan. Provides the remarkable working out in detail in the center of shot and good on periphery. Ideal combination of price and quality. Hand focusing pleasant feature, bonus for creative process lovers. There are universal options: aperture 11, distance is a 1 meter. And you are busy at only composition. I recommend!

[f/1.2] 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.

[12.5 mm] 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.

[12.5 mm] I bought this for my K-50 because it was designed specifically for APS-C format cameras. Absolutely delighted with how it worked during our recent trip to Grand Teton and Yellowstone National Parks. The depth of field is amazing - when shooting in bright light I set the f-stop to 4 or 5.6 in AV mode and then set the lens using the depth of field markings. The K-50 happily chirped every time, telling me it was in focus. During the evenings for night sky shooting all I had to do was open it wide to f/2.8 and set the focus marking to infinity - I tested that during the day time as well. Perfect pinpoint stars near the center and just a trace of astigmatism at the corners - very good performance. Looking forward to using this beauty during future travels that take us into grand buildings, where the ultra-wide rectilinear performance will really be handy. Should have bought one three years ago.