[cyclone3d]

I've seen quite a few posts where people recommend not using the generic infinity capable m42 to k adapters.

I've got a generic one I bought a few years ago off of Ebay and still don't understand what the big deal with the genuine Pentax one is, especially the crazy price the genuine one commands on Ebay.

Generic = $6.12 shipped while the genuine one generally goes for $40+.

Even ones marked as being made in Japan are only $10 - same exact one I have. edit: There is even a Japan marked one for $7.50 shipped.

I even found one that has the ring to push down the pin on auto only m42 lenses for a whopping $7.20.

Mine can be installed and removed easily without the little tool it came with, which is the main plus I hear about the genuine Pentax adapters.

Does somebody have pics of the genuine adapter that I could compare to my generic one? The pic in the lens review section only has one picture and it doesn't look any different than my generic one.

[SpecialK]

If you've read quite a few posts, then you should already know the answer :-)

Some generics do not allow focusing to infinity.

[panoguy]

You probably won't be able to tell the difference from a photograph. I've had many different Chinese M42-PK adapters, and a few Japan-made (even "brand name" like Marumi), as well as the "genuine" Pentax adapter.

***The reason people recommend the genuine Pentax is that there is no variability.*** You know what you're getting and they always work because they invented both of the mounts!

That doesn't mean all generic copies will be "bad." My Marumi ($15) is only a little sharp on the machined edges, and one "flanged," non-infinity adapter I got from China ($3) is very well made and great for a portrait lens. However, some of my cheap infinity adapters wouldn't work with all of my screwmount lenses (either uneven threads or not enough threads!), or worse, the adapter was sloppily machined so the lens was upside down when fully screwed on (and I couldn't easily read the distance scale or change the aperture), and in almost all cases the little spring-lock would bend or fail on the generic ones (but I remove that anyhow).

So, Pentax M42-PK adapter = works every time and is perfectly made.
Other brands = you won't know until you try it.

Up to you, of course. I've tried many generics because I fix the adapter to the M42 lens to make it a PK mount in my bag. No fiddling with that one adapter, and easy to switch from DA to Tak.

[jatrax]

As Panoguy says: Pentax = always works.

I have two Pentax adapters, one for each kit bag and they always work, always fit perfect. I have a number of generic adapters, some work almost as good as the Pentax one, some are abysmal with poor machining, threads that are cut sloppily and sharp edges.

Maybe the generic ones have gotten better, I have not bought one for some time but I remember a post here, maybe a year ago where somebody had bought a generic adapter and had the threads crossed on the lens. They were trying to get it off without ruining the lens, not sure how that worked out. No way I'm taking a chance like that with any of my glass.

Also, some of the generic ones do not focus to infinity because they have a flange that does not seat into the k-mount. I have one of these and use it on my bellows setup where it actually works great, infinity focus not being needed for macro.

[cyclone3d]

If you've read quite a few posts, then you should already know the answer :-)

Some generics do not allow focusing to infinity.

I am only talking about the ones sold as supporting infinity focus - the non-flanged ones.

[cyclone3d]

Maybe I just got lucky with the first adapter I bought. I did make sure it was a "Japan" made one.

Do The Pentax branded adapters work fine if you attach them to the lens first and then attach the lens to the camera?

The person that cross threaded the lens to the adapter.. pure user error unless it was a different thread pitch. Even then, it would have taken quite a bit of force to screw the lens onto the adapter.

Cross-threading doesn't just happen by itself. It requires that the person put a lot more than normal force into screwing things together incorrectly.

[m42man]

...Do The Pentax branded adapters work fine if you attach them to the lens first and then attach the lens to the camera?

Yes, in fact that's how you're recommended to install it on the camera. Sounds like you've been lucky with your purchase, as one of the key features to look out for is ease of removal without a tool. The other key feature is an abruptly squared-off end to one of the 3 "ears" which mate to the camera mount. I don't think many of the third-party copies actually have this feature, which may mean they're a bit prone to jamming.

[newarts]

Yes, in fact that's how you're recommended to install it on the camera. Sounds like you've been lucky with your purchase, as one of the key features to look out for is ease of removal without a tool. The other key feature is an abruptly squared-off end to one of the 3 "ears" which mate to the camera mount. I don't think many of the third-party copies actually have this feature, which may mean they're a bit prone to jamming.

The squared off ear end near the spring clip seems to help prevent my Pentax Brand adapter from over-rotating (although it will do so if you try enough times). This squared off ear is the only significant difference I've found when critically comparing the Pentax brand adapter with a few others. I modified a non-Pentax adapter by squaring off the ear ends and it mitigated the over-rotation problem.

Pentax adapter ear on the left:

[newarts]

The person that cross threaded the lens to the adapter.. pure user error unless it was a different thread pitch. Even then, it would have taken quite a bit of force to screw the lens onto the adapter.

It could have been a "T-mount" lens - same diameter as m42 but finer pitch. The two are often confused.

[RioRico]

I've given this answer before: If you have very few M42 lenses or plan to use just one M42 for an extended time, the Official Pentax IF (infinity focus) adapter is best. I bought a new one for US$40 and a used one for US$10. These are safe and secure and a little tedious to use. To enable a lens for CIF, see below.

If you have many many M42 lenses and want to use them as if they were native PK-mount, get a few dozen clone IF adapters. Remove the screw and clip or YOU WILL GO APESH!T! Now screw the adapter onto the lensmount and use a PK rear lens cap as a 'wrench' to tighten it. To use catch-in-focus (CIF), first stick a bit of metal tape on the lens base to (safely) cover the camera-mount contacts. You may need to experiment a bit to get the tape placement right.

If you have M42 macro tubes and/or bellows, or cheap telephotos that focus past infinity, or macro or close-up or portrait lenses where infinity doesn't matter, or even teles where your nearer subjects don't demand infinity focus, then get some cheap safe wide-flanged NIF (non-infinity-focus) adapters. These CANNOT get stuck on the camera -- unless you try the CIF metal tape trick with them. If the adapters are shiny, fine. If they are black, DO NOT put metal tape on them. Same with black cheap PK macro tubes -- adding thickness to their camera-mount sides WILL cause them to jam. Just use a file to remove some of the black paint, again to (safely) short the contact pins.

[Ratmagiclady]

If you do get any cheap one, be sure to deburr with some hard leather like a belt, and clean threads with some oil and a rag until they're clean. Won't make em shaped right, if there's an error there, but you don't want metal filings near your digital sensor.

[mikeSF]

i have at least one M42 adapter for every M42 lens i own, a mix of pentax and off brand. I'll say that some of the knockoffs are better quality/performance than the genuine adapter and some are not. for $6, though, i find the risk to be very small, especially if you want one for every lens. good luck.

[JeffJS]

Ever since I had a Generic get stuck on my K10d, I've used nothing but Genuine. I sometimes (read always) fail to understand why people will pay a fortune for cameras and lenses and look for the cheapest worse made POS accessories that exist to use with them. Maybe that's just me though.

[Lowell Goudge]

I presently have 3 M42 adaptors.

The first I ever got was an origonal Pentax one. Paid the price and have no complaints.

I have used 3-4 flanged adaptors, but not for mounting M42 lenses. I use them for converting lenses that do not have either M42 or K mount bases to K mount lenses. the flange helpos with this and I manage infinity focus by controlling the shims I put under the mount before attachment.

I have one Bower Generic M42 adaptor, and bought it even after reading all the complaints. What I find with the bower adaptor is the following.
- the adaptor machining is a little tight on the screw thread, I think because it is machined to size before anodizing, which leads to a tight fit thread.
- there is machining swarth on the parts, and burred edges that will drop metal particles into the camera that need to be cleaned before use
- the locking spring does not correctly allign and is a little proud of the mount, which can scratch the lens bases.
- someone else complained the spring tab screw was so long it caused the adaptor to get stuck on the lens (I did not have this issue)
Properly cleaned and a few parts filed, and screws loctited into place the adaptor works OK and has a flange that will activate the auto aperture pin, for lenses without an A/M switch. which is why I got this adaptor in the first place.

In my opinion, the bottom line is before you mount it to a prize lens, inspect it carefully, test it out on a junker etc, and inspect / file off shapr edges.


YOu may ask why all this is necessary, but I will give an analogy. In a woodworking magazine, I read an article about a master craftsman's shop. Although he stressed purchasing quality tools, he disassembled every one and finely dressed all the parts, removed burrs etc, to make it optimal before use. I see no difference here.,

[mikeSF]

Ever since I had a Generic get stuck on my K10d, I've used nothing but Genuine. I sometimes (read always) fail to understand why people will pay a fortune for cameras and lenses and look for the cheapest worse made POS accessories that exist to use with them. Maybe that's just me though.

i kind of look at it the other way...most of my M42 lenses were $10-$25. Please tell my why i would spend $20 for a lens and $39 for the M42 adapter to fit it. I have about 15 screwmount lenses and 15 adapters, that could get ridiculous.

I understand another way to utilize the adapter is to have just one, but if you change between K-mount and screwmount lenses frequently in the field, this gets old very fast, as it becomes a multi-step process.

just a couple cents worth of counterpoint.