If you have an M mount camera, this adapter lets you use the hundreds of Canon lens models made since the late 1980's, many very reasonably priced. The Canon adapter maintains the quick focus of the camera, and was selling at a steep discount on Amazon.

I ordered the 52mm filter because the 30mm f1.4 sigma lens for sony e-mount cameras has a 52mm thread but after lens arrived, I couldn't fit it on.But after-service support was pretty helpful in telling me this

So you finally decided on getting the EOS M (it's flaws considered). I assume you are a canon user, have a couple of good (canon EF/EF-S mount) lens lying around and would like to be able to use those on you EOS M. Just like me, you love your canon dslr but sometimes wish you can travel light but still be able to enjoy the canon ecosystem that you have grown to love. If you are what I assume you are, get this lens adapter.I took a gamble and bought a "like-new" used from a seller at Amazon and was very happy with a purchase. For anything more than $150 I probably would think twice. But I am not taking a start out because of the price. This adapter handles every canon mount lens I threw at it. The build quality is nice. The design (the way it attaches to the eos m; the included, detachable tripod mount) is well thought of... just perfect.

Part 1 - Minolta MD to Sony NEX adapterTechnically, it slightly overshoots infinity but the issue is easily corrected by dialing back the focus ring just a tad --- Not exact but clearly better than not-at-all.Although very light due to extensive aluminum usage, the build quality and fit-and-finish of the adapter is superb. Connections on the lens and camera mount sides are tight and precise --- absolutely, zero slop. The top of the lens release button is flattened making the lens removal process very easy and comfortable.Other notes:- There are no electrical connections so focus and zoom must be done manually on the lens itself- When mounting the lens, turn the adapter clockwise till you hear a "click"- Tested with a Minolta 85mm f/1.7 Rokkor-X MD lens mounted to a Sony a6000 camera-----------------------Part 2 - Nikon Ai to Sony NEX adapterEdit: Based on my positive experience with the Minolta MD adapter, I also purchased the Nikon Ai adapter later.As with the Minolta MD adapter, the Nikon Ai version focuses beyond infinity a tiny bit. Fortunately, the same solution applies - dial back the focus ring and the horizon will become crystal clear. The build quality is impeccable and the finish is smooth and clean of burrs or machine marks. Connections on both sides are taut and precise with zero play.Additional notes for Nikon Ai adapter:- No electrical connections present so focus and zoom must be done manually on the lens.- Unlike the Minolta MD adapter, mounting the lens for Nikon adapter requires a counter-clockwise turn until you hear the "click" of the locking mechanism- Tested with a Nikon Micro Nikkor 55m f/2.8 Ai-S MF lens mounted to a Sony a6000 camera

I do not use these for the UV filter but as a good quality, low cost lens protector. That said:My 1st Tiffen was a 55mm UV Protector I got for the kit lens that came with a Sony a7ii; an FE 28-70. I was so happy with the purchase that I have since purchased three additional Tiffen UV Protection Filters. One is on a Sony E 55-210 I bought used and one is on a Samyang 35mm I bought new. The one I am writing this review for I assume is still on the Sony FE 50mm I bought new but returned and forgot to remove the filter.The point? I treat my lenses, new or used, like I treat a cell phone. That being the phone stays in the box until I have a protective case for them and lenses stay in the box until I have a protective filter to pair them with. And the one I forgot to remove from the returned lens? That is how confident in the Tiffen filters I am. Once I put one on a lens, I never need to think about it again.I have used several brands in several sizes ranging from the cheaper Altura and Polaroid to the mid range Hoya and B & W.Where does Tiffen fit? Well they are no Hoya or B & W but I am no professional photographer. I am an amateur who mostly enjoys street photography when I travel and for my money Tiffen is the best. Yes, you can spend more and get better glass and if you really have reason to worry about ghosting you should look for a higher end lens. That isn't me saying ghosting has been a problem for me. I normally use a lens hood and I think that helps cut down on light reflection. I have noticed some minor issues with it on some shots I have taken in direct bright light conditions but not enough to justify the higher price.I do not stack filters as I haven't had a need to so I can not give an opinion on that topic. I would assume that the risk of ghosting would increase.The short version is this. The Tiffen UV Protection Filter is well made with good quality glass and a metal ring with threading I do not worry will cross thread or strip. They do what I need by protecting my lens. If I was buying a ND or polarizers I might buy a more costly brand but for everyday protection, Tiffen is all I need and the best for my money.Tiffen say it best in their own product description; A small price to pay to protect your investment.

Great adapter, must have. Can't beat the price and works perfect. Allows you to use way more lens on your ef-m mount camera.

It is light in weight. I use it to protect my Sony lens.

This is a great auto focus lens mount adapter. It seems to work flawlessly the few times that I have used it. I would recommend this product.