have had this extremely good lens in my hands for 24 hours and have looked at the first results under LR. I'm really positively surprised. I wasn't expecting this really good BQ, but I was hoping for it. How did I test? With a D850, ISO automatic from ISO64, longest shutter speed 1/30, aperture preselection usually F5.6, everything from the hand and as horizontally and vertically as possible, without using the built-in 3D scales. Time: between 12:30 and 14:00, partly cloudy with sunny intervals. Results: really sharp image, very good drawing and detail resolution, even with backlight and side light (sun) I could not see any "lens spots". As expected, vignetting is strong at 2.8 and stopping down at least one stop has a visibly mitigating effect. Lens correction is available under LR. Here the vignetting and the distortion/compression (which doesn't bother me) in the edge area of the image are corrected. The distortion correction may be a matter of taste. Some image information is lost in the peripheral area, not dramatically. The angle of view is impressive. Real fun. In my opinion, the lens is suitable for open glare. Although the vignetting is visible at 2.8, it can be easily corrected. The more important resolution is central and good to very good at the edges. For close-up shots at F2.8, the lens delivers a nice/pleasant bokeh. The accuracy or accuracy of the AF usually does not play such a decisive role at 14 mm when shooting with F5.6. The AF on my copy works very well/accurately and I couldn't tell any "real" difference between LiveView AF and standard AF, at F2.8 and even at close range. The AF is quiet and fast. I am very happy with the AF. The lens is lightweight, compact and solidly built. An IRIX 15mm, on the other hand, is a heavy chunk. K&F Concept has made a really good product here. A few months ago I bought an IRIX 15mm 2.5, which already showed centering problems during the first tests. My copy of the K&F Concept 14mm is much better centered here than the IRIX mentioned above. If you look closely, I think I see a very slight misalignment. I'm not sure yet. It's only noticeable at 100%, if at all. In my opinion, the K&F Concept is better than the IRIX 15mm and for around 200 euros more you get a well-working AF. I could now sell the IRIX. Or? Well, really, actually, not really. Why? Now, let's get to the things I don't like, are missing, or bother with. However, it should be said in advance that I can live with the following "defects": - no distance display, no aperture range for depth of field. Zero. never. Nothing. (see IRIX 15mm) - no filter thread or slot for gelatine filter (see IRIX 15mm) - 5 year guarantee only for Portugal, Andorra and Spain. Why? Compared to the very good Sigma 24mm 1.4 ART, I would like to boldly claim that the K&F Concept comes very close in terms of resolution/sharpness. In terms of size, the K&F Concept is even more compact than the Sigma 24mm Art. Conclusion: after today's photo tour and the photos I have just viewed, even below 100%, I will no longer give up the K&F Concept. It's now one of my favorite lenses. The IRIX 15mm will probably have to be in the showcase very often now and only taken out when I have to or want to work with filters. I bought the lens myself, it was not provided to me free of charge, I do not work for or at K&F Concept and there are no conflicts of interest. I have only given my first subjective impressions here without laboratory measurements.