Exactly what I was looking for, a light, bright UWW to be able to photograph stars. Otherwise, the wide-angle range is covered several times for me (Nikon 16-35, Nikon 20mm/1.8, Sigma 12-24mm second version). So I ordered it and tried it out, I got hold of one from a Dutch retailer via Amazon in September, even with a 5-year guarantee after registration. My test setup in the basement, a wall unit with a test panel in the middle and one in each corner. I had already tested other lenses with it and discovered weaknesses (slightly muddy corners due to decentering) that I had not noticed in everyday life. In any case, the surprise, the K&F Concept already shows almost the same sharpness in all corners as in the middle at an aperture of 2.8! The further stopping down mainly brings an improvement in vignetting, from f4 this is almost non-existent (there is currently no lens profile for the Nikon version). For this test, the camera (D800) was of course placed on a tripod and aligned with the virtual horizon. The parallelism to the wall was checked with a meter stick and an auxiliary ruler. The so-called glacier fracture test no longer works with the extreme focal length, since the corners warp due to the tilt of the camera when panning (physically caused). Enough theory, the moment of truth came in the Dolomites during one of my first attempts at milky way photography. The conditions were ideal, the result fantastic (first picture, not the final edit yet). The last image shows a 100% crop of the same but unedited RAW image from the top right corner(!), only the exposure was increased by one stop. I would be happy if there would soon be a lens profile from K&F Concept for the Nikon version, unfortunately nobody answered my email. Otherwise I am very pleased with the results. I sent the Irix 15mm back straight away, it was neither visually nor haptically appealing, only the filter suitability would have spoken for it.

I bought the lens to use it mainly indoors in churches. The large angle of view also allows for unusual perspectives. For the price, the lens is excellently corrected, straight lines stay straight. Well aligned, converging lines are kept within limits. I see the bulky appearance as a disadvantage. Takes up a lot of space in the camera bag. The front lens is curved, which does not allow filters. The autofocus is quiet and fast. The feel is definitely top and is in no way inferior to higher-priced optics.

Tested the 14mm K&F Concept on a Nikon D750. The workmanship looks solid and also feels good. The positive: The size is very comfortable and the weight is more than acceptable. The image quality is absolutely convincing for this price. But I only tested aperture f8.0 and 9.5. Anything below f8.0 is absolutely not important to me. Since I only want to work hyperfocally at this focal length. Anything above f9.5 is outside the beneficial aperture for a 24MPix sensor, so nothing gets better when stopping down. My lens was surprisingly well adjusted in terms of sharpness. It was still well sharp in the corners and gave a good drawing. I tested it against my Tamron 15-30, 2.8. And the K&F Concept did relatively well. The autofocus is quite fast, but that doesn't really interest me with a UWW. The vision is impressive.....compared to my 15mm Tamron, the 14mm of the K&F Concept is amazing. The negative: This lens offers nothing more for good, old photo art. The AF is controlled by a motor, looks and feels great, but makes absolutely no sense to someone adjusting manually. Since there is no longer a distance scale here, I cannot use the lens hyperfocally. In very dark rooms, caves etc. you need a scale, otherwise it won't work..... In terms of sharpness, I can't recommend the lens for sensors beyond 25MPix. Compared to the Tamron 15-30mm, it already shows clear weaknesses in resolution....and that doesn't get any better with larger sensors, on the contrary. The big ones then rigorously point out the weaknesses. Conclusion: Great little lens, with enough sharpness right into the corners (if you can get a good one). Small and handy at a very reasonable price for this focal length. A top choice for landscape photography with sufficient light. For dark locations, you first have to turn on the light to see how the sharpness fades.

Probably not a lens for full professionals. But for hobby photographers and also for ambitious hobby photographers, the lens is also a good choice in terms of price. It definitely gives the creativity more distinct possibilities.

As a long-time amateur photographer, I love this super wide angle, which allows for amazing shots with almost no distortion and with a sharpness that would envy more well-known and, above all, much more expensive brands. The autofocus is a bit indecisive at times, but that's somewhat normal in areas without relief and with such a short focal length. Careful workmanship, light weight, in my full size, it makes me very satisfied when I see how the material holds up over time. Attention, it is not possible to screw in a filter in front.

Nice surprise that this goal! Used with a Nikon D750 Perfect compatibility, the autofocus works perfectly, Nice brightness, perfect for architecture or for original panoramic views. And all this at a very gentle price compared to the untouchable Nikon, as well as the Sigma. Having had the different models, the shots obtained are all quite honorable... and are perfectly suited to my photographic work

It's a great destination with good value for money

Excellent performance in terms of deformation, stitching and color. The ultra-wide angle and very large depth of field enable breathtaking landscape images with a perfectly sharp foreground. Its absence of deformation is also a very good point in architectural photography. Autofocus works well, but we'd like a graduated ring for manual focus as the large depth of field doesn't really allow for precise focusing through the optical viewfinder. Autofocus is essential in a SLR camera.

positive: hardly any flares (see photo), razor-sharp photos, perfect autofocus, also very good at close range. Aperture stars from f. 14 possible without any problems. Negative: clear vignetting with a blue sky at f/2.8, which is hardly visible from f/4. Definitely a clear buy recommendation. 1 star less because of the vignetting, which is somewhat correctable. Lightroom CC corrects without any problems.

For a long time I was looking for an ultra wide-angle fixed focal length for landscape and astrophotography. After a long research I bought this lens in the MM. Unfortunately, the first attempt was not surprising because the AF motor was probably defective. OK, can happen! It was quickly replaced with no problems. The second try was a lot better. Above all, the sharpness and the autofocus are great. I tested the sharpness with the Tamron 15-30 and was very impressed. Of course, the Tamron is better in terms of resolution, but the K&F Concept does not take too much resolution compared to the Tamron. Purely visual impression with the help of Photoshop. The vignette is clearly visible at f2.8. Depending on the subject, it can be installed creatively or starts the lens correction in PS. See Ghostbuster pictures. In the case of manual focusing, the lens groups are not manually shifted mechanically; this is done using an electric motor. The close-up limit is approx. 20cm from the sensor level and is therefore very well suited for close-ups. I deliberately do not use the term macro. What are the advantages compared to the Tamron: Clearly the price and the weight. The Tamron scores with the slightly better resolution and the image stabilizer. In terms of processing, the K&F Concept is quite good, but cannot quite shake hands with the Tamron. For everyone who is looking for a light UWW and does not want to lug around more than 1 kg of glass, the K&F Concept is more than well advised. Like any lens, it also has advantages and disadvantages. Have fun looking at my pictures.