[Manual Focus] 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.

[f/22] I haven't really gotten a chance to use it, other then a few test shots around the house. Taking it camping this weekend to get some milky way and landscape shots so I'll know more after that. Rating it 5 stars for now because of the timely shipping and the feel of the lens, the focus is smooth, and the lens feels well built.

[f/2.8] Good lens...

[APS-C] 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/2.8] great for closeups, portrait epic style and landscape... but most important to me... to capture the milky way at night...

[1.2 lb] 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.

[109.5°] I wanted a wide angle lens to finish my lens line on the wide end. I wanted something pretty fast with good optics. This lens fit the bill.


I was a little hesitant to get a strictly manual lens but I have had no issues using the manual features. Plus, my Panasonic G85 does some auto functions even with the full manual lens.


The lens was longer and heavier than I expected. It's about the same length as my 100-300mm Lumix lens and a few ounces heavier. This has not been an issue since the f/2.8 handles low light pretty well even without a tripod. I really expected to see a significant fisheye distortion but was very pleasantly surprised at how little there is. This lens is already seeing use.

[109.5°] 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.