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.