Fotodiox Lens Mount Adapter Pentax K AF Lens to MFT (Micro-4/3, M4/3) Mount Mirrorless Camera (Such as OM-D E-M10, Lumix GH4, and BMPCC) w/Aperture Control Dial

USE> You can use this adapter to adapt ANY K-mount lens to any micro 4/3 camera (CMA: with a few possible weird exceptions that I don't know anything about)> In effect this is the same adapter as a  Fotodiox Lens Mount Adapter, Pentax K (PK) to Micro 4/3 Olympus PEN and Panasonic Lumix Cameras , with the addition of (manual) aperture control, which is essential for lenses without aperture rings, and helpful for lenses with aperture rings.USE WITH K-MOUNT LENSES WITHOUT APERTURE RINGSThis adapter has no electrical connections with the camera (nor does any other adapter), so you cannot set the aperture from the camera. Pentax "digital" lenses do not have aperture rings. In effect this adapter provides an aperture ring with click-stops, and provides have some control over the aperture of your lens. However, the click-stops on this adapter aperture ring is unmarked, so you really don't know what aperture you are stoping down to.GUESTIMATING THE APERATURE STOPS when using K-mount lenses without aperture ringsIt's 6 clicks (of the adapter aperture ring) from fully closed to wide open regardless of the range of the lens aperture. So if your lens has a range of 7 stops (say, f2 to f16) then you get 1 stop per click (of the adapter aperture ring). If your lens has a range of 4 stops (say, f4 to 11) you get 1/2 stop per click (of the adapter aperture ring). In most other cases, each click is a little over 1/2 f-stop. Since there are no marks (which the manufacturer could easily add), you have to count the clicks.USE WITH K-MOUNT LENSES WITH APERATURE RINGS> If your K-mount lens has an aperture ring, then you could use the cheaper  Fotodiox Lens Mount Adapter, Pentax K (PK) to Micro 4/3 Olympus PEN and Panasonic Lumix Cameras  adapter---you don't really need to use the adapter aperture ring.> However, the aperture control is useful as a "preset ring". You can set the aperture you want to use on your lens, then using the aperture ring of the adapter, open up to focus (to take advantage of the shallower depth of field), then stop down to take the photo---without having to look at the aperture setting on your lens to know what stop you are using.> The difference between the adapter aperture and a traditional preset ring is that the traditional preset rings were very loose and very quick. The aperture ring on this adapter is stiff and slow (with the incremental click stops) which reduces its convenience as a "preset ring". The added potential convenience is small. Even with the manual adapter (without the aperture ring) you can focus wide open and then stop down to take your picture by counting the click-stops of the aperture ring of your lens.USE WITH PENTAX SCREW-MOUNT LENSES> If you happen to have a screw to K-mount adapter, and Pentax screw-mount lenses (all of which have aperture rings), you CAN use this adapter, but the adapter's aperture ring will do NOTHING. The lenses will still focus to infinity, and you'll still lack auto-focus and auto-diaphragm.WHAT IS A PRESET RING?Back in the 1960s or so, before automatic aperture lenses were common, many lenses came with "preset" rings. The "preset" rings allowed you to meter "stopped down" at the aperture you wanted to use, then flick wide open to focus (taking advantage of the shallower depth of field), then flick back down to take the picture---it worked pretty well once you got used to it. This was particularly important before metering was fully automatic because you had to meter at the f-stop you took the picture. Even as late as 2008 Nikon perspective lenses were non-automatic and had preset rings. Many inexpensive long telephoto lenses still have preset rings, for example:  Opteka High Definition 500mm f/8 Preset Telephoto Lens for Nikon Digital & Film SLR Cameras USE WITH A PANASONIC LUMIX GX7 (and probably other Panasonic Lumix Cameras)> You need to set the camera to operated "without a lens". Menu > Custom settings (C with a wrench) > Shoot w/o lens > on> You will also be prompted "current focal length setting 35mm: change the setting? The camera needs to know the focal length in order to calculate a suggested shutter speed for automatic operation. So, it's a good idea to tell it the focal length of your lens.BOTTOM LINE> This is the adapter to use with K-mount lenses WITHOUT aperture rings (such as the "digital" lenses). You CAN also use other K-mount (and even screw-mount, with screw-to-K adapter) mount lenses with this adapter--but the cheaper Fotodiox adapter works just as well with those.> You can continue to use your Pentax-K lenses but the lack of an auto-diaphragm (aperture) and auto-focus is a VERY considerable inconvenience.> Click on “Stoney” just below the product title to see my other reviews, or leave a comment to ask a question.

I found it to be exactly as advertised. Everything works.Note that you don't have access to auto-focus when using this adapter. But generally speaking it is nice to be able to regain access to good lenses.Otherwise the release button for the lenses needs to be pulled back and not pushed which was my intuitive attempt. At first I thought my lens was going to be stuck. After a few tries I realized how the release button operated.

I looked around quite a bit to find the right adaptor and chose this one. It's very solid and well made. It's also a great price compared to others. I used it to adapt old Pentax K1000 lenses on my Lumix GH5. I'm very happy so far!One note, though, regarding how to take the adaptor adaptor off the lens. I was initially thinking that the adaptor had gotten stuck on the lens, because I thought the silver button on the adaptor was actually a button the press down on to and then twist the adaptor to take it off. This is not the case. The way to take the adaptor off is: hold the lens with the adaptor facing you and *slide* the silver button toward you and then twist the adaptor to take it off the lens.Hoping to save others from running into what I did. This is a great adaptor and there are so many K-mount lenses available at very reasonable prices at camera stores and pawn shops.

This adapter allows one to mount their Pentax lenses to their micro 4/3rds camera - in my case, an Olympus Pen E-P1. It's important to note that while your lenses may be digital/autofocus, this adapter does not map electrical contacts through to the lens. This means that you'll be manually focusing your lenses when they're mounted. (I don't know of any adapter that allows a Pentax lens to autofocus as if it were native). The build quality seems good and the bayonet action between the adapter and lenses is tight - almost excessively so. Action between the adapter and my camera body is smooth; there's definitely no slop in my setups.The aperture dial may not necessarily be something you need; it simply engages or disengages the aperture on the lens. It has two settings - locked or open. One opens the aperture completely regardless of the selection on the lens, and the other allows the lens aperture to function normally. I do have trouble achieving infinity focus with some very small/extreme aperture settings on an 80-200mm lens - at 200mm it couldn't reach infinity in the f22 to f32 range. F16 and larger was fine. Since those aren't realistic settings for shooting (full zoom + little light allowed) I give the adapter a pass on that. My 28-80mm lens will focus fine fully extended at f22. Overall, this seems like a high quality adapter that performs as expected.

I have a pretty large collection of Pentax lenses and this adapter allows me to use them with my Panasonic Lumix G-2 and G-3. It's simple to use and the price is right. The aperture control is a necessary feature if you have modern lenses without the aperture ring. But this item works with all of the lenses I have, both new and old. If you buy this adapter I recommend that you buy exta caps for both ends because it is necessary to keep dirt out of the inside at all times even in storage else the dirt can migrate to your sensor if you take this adapter on an off on a regular basis. Note that your camera will be in the manual mode when you use this adapter since there are no electronic connections between the adapter and your camera.

The Pentax lens fits on it beautifully. I can't test if the aperture ring works as I can't get this to fit on my Micro Four Thirds camera (Olympus OM-D E-M10). I've written to Fotodiox to see how they might be able to help me.

Hmm. Seems nicely made, secure fit to both camera body and lens. But, for me at least it focuses ‘past’ infinity. That’s with a Pentax 50mm prime and a Tamron 80-210 zoom fitted to an OM-D E-M10 Mark 2. In some ways it doesn’t matter that much as you’re focusing manually anyway, but for distant subjects it means you can’t just ‘set and forget’ the focus. Not sure whether to send it back or not, given a lot of the other Pentax fit adapters for micro 4/3 seem a lot more expensive. And may have the same problem of course...

I own an Olympus OMD-EM5 and I purchased this adapter to use a couple of legacy Vivitar (Pentax-K mount) lenses. I was searching for a good quality, but reasonably priced adapter, since both of those lenses are long zooms and I wouldn't use them very often. After some research, and having read various good reviews for this adapter around the internet, I took the plunge. I was a little concerned about the sturdiness and general manufacture before its arrival, because I had already owned another high quality (but more expensive) adapter for Leica-M mount from another company. Whatever concern I had vanished as soon as the adapter arrived and I tried it on my camera. Build is all-metal and very solid, as is the attaching and general sturdiness. The whole lens-adapter assembly is not flimsy at all (and it is quite a heavy lens). The aperture controller built into the adapter is a nice touch as well.Overall I'm very satisfied with this one, and I would highly recommend it for anyone looking for a good adapter that they can trust with their valuable lenses, without paying a fortune for it.

Not quite as illustrated (all black and lever lens release) but that doesn't matter. Works perfectly and the click stops on the way to closing down from max to min aperture are a real help when using lenses without an aperture ring. Bought this to use with my Olympus OM-D E-M1 and Pentax 100mm macro WR and the combination works like a dream. Excellent value for money.

Cette bague permet de fermer manuellement le diaphragme des objectifs Pentax modernes, qui n'ont pas de commande manuelle du diaphragme.Fonctionnement correct sur mes deux boîtiers micro 4/3 Panasonic GM5 et G7, mais peu pratique.La première bague livrée était décentrée et présentait du jeu qui la rendait inutilisable (photos floues d'un côté). Remplacée immédiatement par le SAV, la nouvelle présente un design différend qui semble plus robuste, et fonctionne correctement.

Très bonne qualité pour cette bague toute en métal. Pas de résidus de métal qui pourrait salir le capteur.Fonctionne parfaitement et est même moins longue que son équivalent sans bague d'ouverture pour les objectifs modernes.La bague d'ouverture est un poil trop dure pour être utilisée confortablement, mais elle remplit sa tâche lors de l'utilisation avec des objectifs sans bague d'ouverture (les objectifs Pentax modernes, quoi).Testé avec un Pentax DA 35mm f2.4 fonctionne parfaitement.