Despite the mention in the description, saying that is not good for wide angle lenses, I purchased it for a Viltrox 16mm f:1,8, EF mount. The results are outstanding across the entire range of the filter. No X cross, no vigneting. At least for this specific lens, the filter is perfect. Is true, the size of the barell is twice the size of the front lens, leaving enough room for any kind of filter.

have a Sony A7iii and I was looking for a good adapter for my 2 Canon lenses, 85mm f/1.2 and 11-24mm wide angle lens. This K&F Concept Adapter fits my Sony A7iii well and supports the lenses. I was skeptical about the sharpness of the photos. However, this adapter really nails the sharpness. It's better not to use the widest aperture, because lenses from other manufacturers work extremely poorly. Both sample photos were taken with this adapter. The shot in Florida was taken with the wide-angle lens. The mountains are recorded with 85mm. Autofocus is excellent on a 7iii body, so I didn't see any significant difference between using the adapter and the native lens. Eyefocus works very well even in low light conditions. The good thing is that I was expecting a lot of vignette, but I was surprised to find out that this lens doesn't produce a large amount of vignette. So the bottom line is that you should give this adapter a try. It fits well, not too tight like some cheap adapters. The build quality is really good. Happy clicking!

The adapter works very well and all lenses from wide angle to tele and tamron to sigma worked with the camera without any problems. I even found the Canon EOS M's sluggish autofocus to be a little quicker. Now I can use my Canon 60D and the EOS M together without having to change lenses every time. Clear purchase recommendation.

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.

Made from high quality materials. Precision built. It offered the least amount of resistance I've had when screwing on a new filter. It's very thin so it doesn't interfere with wide-angle lenses (as much as possible).

Using a full-frame DSLR, I made side-by-side pixel-level comparisons between shots with and without a filter. One photo was a wide angle shot of the included sky on a high UV day.

Results: Well, I didn't see any difference in color or richness in the high-UV shot, so I wouldn't buy it just for that. Most of the time, people just buy these as lens protectors (and believe me, they've saved my bacon a number of times on high-end lenses now!). As a lens protector, you want it to be as unobtrusive as possible, and I'm happy to report that I can't tell a significant difference in any test shot - color balance, sharpness, contrast - they're all so close I've never been could definitely say that every tiny difference was due to the filter.

ATTENTION! This filter is not compatible with wide-angle lenses.
On my Sigma 16mm it produces a blue X when set to ND1000.
The manufacturer was very nice and offered me a replacement filter.

WARNING! This filter is not compatible with wide-angle lenses.
On my Sigma 16mm it creates this blue X when set to ND1000.
The manufacturer was very nice and offered me a replacement filter.

ATTENTION! This filter is not compatible with wide-angle lenses.
On my Sigma 16mm it produces a blue X when set to ND1000.
The manufacturer was very nice and offered me a replacement filter.

WARNING! This filter is not compatible with wide-angle lenses.
On my Sigma 16 mm it produces this blue X when set to ND1000.
The manufacturer was very kind and offered me a replacement filter.

A really good tripod, holds my Nikon D 850 with a wide-angle lens, the 14-24mm, f2, which is no lightweight bombs. A short center column without the second head would have been ideal. Highly recommended as a trip and hiking tripod is in any case the customer support, very quick response, and fair to the customer