Works as advertised. Fits the Fuji opening tight and easy to insert. Found that pictures are a bit darker and I have to raise up the exposure. I am using with Helios 44m-4 58 mm 1.2. Focus is great but manual of course.

I ordered the K&F M42 to Fuji FX adapter not knowing whether it would work well with the old Helios and Jupiter lenses I was hoping to use. It works perfectly!The adapter's an all metal build and feels well made and sturdy. It fits snuggly with the lens and the body of the camera (in my case the Fuji X-T10), there's no wiggle or movement once mounted.The adapter has a removable flange for those lenses that have an aperture pin that needs pressing in order to shoot anything but wide open. No need to modify the lenses to keep the pin pressed which is great! I didn't see any reviews that mentioned the flange, so was extremely happy to discover it was there.I haven't had any issues with focus to infinity using the adapter on any of the M42 lenses I've tried. They all appear to work perfectly.Obviously all lenses will be manual focus only, but if you're buying one of these adapters I'd expect you already know that. Set the camera to shoot without lens, and switch the focal lenth to that of your lens and you're off! Focus peaking also works a treat with these older lenses.

Excellent adapters would highly recommend

Works well and is quite robust

If you have some older lenses kicking around (M42 threaded with 1mm pitch (M42x1), They will fit right into this adapter and you will have lots of fun with your x mount Fuji camera!. Adapter is quality made steel and unlike other aluminum/powder coated ones, this will not gouge/score your camera mount. Your lens must have it's own aperture ring. Some lenses may have a "pin" stick out, which needs to be depressed in order to work (for the aperture), be glad, this adapter has a shoulder built just below the threads inside, and, it will do the job!

Works perfectly with my X-T10 and my M42 lenses. My 50mm 1.4 stay on the Fuji most of the time, and focus peaking makes manual focus a breeze.

This adapter is great value for money. It is reassuringly solid and sturdy and does exactly as it should - allows you to mount your M42 lenses on your Fuji X bodies. For just a few quid you have access to a huge wealth of wonderful old lenses which can be bought at very reasonable prices because people don't want to focus manually any more - or maybe you have some M42 lenses stashed in the loft somewhere which you haven't used in years.In my case I have a Helios 44M (cheap as chips from eBay recently) and a couple of Super Takumar lenses handed down to me by my aunt and I believe about the same age as I am.I have been using this on an X-Pro1 and loving the results. Pop the adapter on, pop the lens on, switch to manual focussing and make sure you have focus peaking enabled on your camera. I found it much easier to use these vintage (and superb) lenses on my X-Pro1 with this adapter than I did with my EOS 6D - manual focussing is made a doddle. No reason to pay more than this, I'm tempted to get one for each M42 lens I own.I've attached a photo of a carved stone head from a church window taken using this adapter when I had the Helios 44M attached to it. This was shot with the Helios wide open at f2, manually focussed (of course) using the focus peaking feature of the X-Pro1. Focus nailed on the eye.

Excellent product but over priced

Got this in today for my Fuji X-E1 and I'm very happy with it. I previously bought another adapter from a different manufacturer and that one had a very annoying play on the camera mount - this one on the other hand is rock solid both on the body and on the lens. It's well finished and has a pleasant heft, it's also fairly bulky but I find that a positive - the outer edge, when mounted, lines up exactly with the bottom plate of the X-E1 and provides extra support, so that when you put the camera down it sits level instead of tilting forward. Recommended.

If you have a Fuji X mirror-less camera and also some old M42 screw thread lenses, then this is the kit for you. Fit this between the camera and the lens and you have a perfect, stable conjunction between the two.It has been made out of what appear to be good materials, brass I believe, with what appears to be good metal mounts at either end.There is, of course a down side to using these adapters and that is that you have to manually focus the lens, manually set the aperture, and because of the crop factor of the APS-C sensor a 50mm lens is halved again and becomes a brilliant 75mm portrait lens, but with the advantages of the 50mm lens - in other words the depth of field remains the same, as does the aperture so you do not lose any speed of the lens with this adapter. For an example if the 50mm lens was a f1.4, then on this adapter it becomes a 75mm f1.4!! Try buying one of those for this sort of money.Many may find this a backward step, but it is something that you soon get used to doingThe advantages are that M42 screw thread lenses can still be acquired cheaply by today's standards, some as cheap as £20-30. Add the prices of the adapter and you still have a very cheap lens, especially when you consider that Fuji XF lenses tend to sell at about £500-600, and remember a lot of these old lenses are built solidly of metal and glass with hardly a glimpse of plastic anywhere. Treated well will last a lifetime as well as given brilliant results.