[pentaxus]

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There once was a company that made a bellows with interchangeable mounts for front and back. You could mount any lens in front and mount the bellows on any camera. I think it was a Spiratone product. They sold all kinds of unusual products but went out of business in 1990.

[Not a Number]

The problem with cobbling together an adapter from extension tubes is the diameters involved. Here's an Asahi Pentax M42 Auto Extension tube sitting on top (bottom?) of the PENTAX Auto Extension Tube Set K.



And given the prices that you can get for the Tube Set K after the time and effort to jury-rig something you may as well spend the extra money buy a Auto Bellows K/M/A. And that would give you the convenience of being able to stop down/open up the iris with the button on the bellows or with a cable release.

You might try some of the $5 extension tubes found on eBay. The the male/female mount parts are screwed into simple rings on some of them.

I don't think I'd trust any of my lenses to a mount held together with super glue or even epoxy

[kypfer]

There once was a company that made a bellows with interchangeable mounts for front and back. You could mount any lens in front and mount the bellows on any camera. I think it was a Spiratone product. They sold all kinds of unusual products but went out of business in 1990.

B.P.M. (Butterfield Photographic Manufacturing Co.) in the UK also made bellows with interchangeable mounts … I have mounts for PK and Praktina for mine. Other mounts are often available on eBay, but they're not cheap, and have frequently been separated into individual components, (camera mount and lens mount), so you need to check you're buying what you want


Addenda :
According to the instructions with my bellows, there was also a "Mount Connector" available "to hold any two B.P.M. interchangeable mounts back to back to enable it to be used as a short extension tube."
So, in theory at any rate, a PK to M42 adaptor was still available commercially in March '78 (publication date on instructions) … find one if you can

[Not a Number]

Some of the bellows I've seen that have various mount adapters for them have a male M42 or T-mount thread on the front of the bellows. So even if you found one of these adapters you have to find a "sex changer" M42/T-mount adapter. I know you can find the T-mount but an M42 sex changer might be more difficult to find.

Again, in my opinion, the simplest option is to buy a K-mount bellows. provided you are using a K-mount body. I have both the Pentax Auto Bellows (M42) and Auto Bellows-A. Just use the K-mount to M42 adapter for the screw-mount lenses on the K-mount bellows.

The K-mount bellows attaches more solidly to a K-mount body than the screwmount bellows with OEM adapter. There is some rotational play with the body when using the OEM adapter no matter how tightly you screw it down. The solution would be to use a flanged adapter that has the K-mount locking pin slot. After I got my Auto Bellows-A I hardly ever use the M42 bellows. The only advantage with the M42 Auto Bellows over the K-mount bellows is that I can use a cable release to stop-down my Auto screw mount lenses.

[UncleVanya]

You might try some of the $5 extension tubes found on eBay. The the male/female mount parts are screwed into simple rings on some of them.

That’s what I was suggesting. A step ring with the appropriate threading could mate the two parts.

[vonBaloney]

There are K-mount to T-mount adapters (made for bellows), which coupled with a T-mount to m42 will get you there (with some significant extension leaving you only macros on any non-telephoto focal length lens). Possibly there is a direct to m42 version somewhere, but again the extension will be significant.

[Wheatfield]

Anyone ever hear of an adapter than converts a Pentax K lens to fit into a M42 body or accessory like the Pentax Bellows II. No, I do not have to focus at infinity and yes, that is correct, an adapter ring that converts K to M42, not the other way (I already have plenty of those adapter rings)

I have one. I think it was made by Spiratone. Anyway, it is, in effect, a short extension tube with an M42 male thread on the back and a K body bayonet mount on the front.

[Kingman]

use the K/M lens reversed?
Get an M42 to 49 or 52mm filter thread adaptor, and then step up or step down rings as needed for the lens you want to use?

My goal was to use test out the macro usefulness of the bellows with my UWA K lenses. Reverse mounting of UWA lenses is not always possible nor would it accomplish the intended UWA Macro with a a bellow unit. Yes, I could buy a Pentax Bellows K, but I already have a Pentax Bellows II (M42) mount for the lens. Obviously adapting the new K digital bodies to the Bellows II is not an issue.

[vonBaloney]

I have one. I think it was made by Spiratone. Anyway, it is, in effect, a short extension tube with an M42 male thread on the back and a K body bayonet mount on the front.

Are you sure that it isn't a T-mount thread (not a true m42)? (The Spiratone "T-Flange for Pentax K" is not too hard to find, which is K -> Tmount and made for the Spiratone Macrobel T-mount Bellows system I think.) I don't think I've seen an m42 one, but that would be useful. The Vivitar Bellows system was a similar T-mount system, and you can find Vivitar branded K-Tmount adapters also. (As well as Nikon, Minolta, etc to T-mount for the same bellows)

[Wheatfield]

Are you sure that it isn't a T-mount thread (not a true m42)? (The Spiratone "T-Flange for Pentax K" is not too hard to find, which is K -> Tmount and made for the Spiratone Macrobel T-mount Bellows system I think.) I don't think I've seen an m42 one, but that would be useful. The Vivitar Bellows system was a similar T-mount system, and you can find Vivitar branded K-Tmount adapters also. (As well as Nikon, Minolta, etc to T-mount for the same bellows)

It might be. I tried putting it onto a Spotmatic, and the threads don't quite line up. It's close, almost like chasing the threads would allow it to mount, but it isn't quite the same pitch, though it does appear to be the same diameter.
Thirty seconds on Google has given me the answer, The T mount is an M42 x 0.74mm thread, the Pentax screw mount is M42 x 1.0mm thread.
And there you go. What I have is a T mount to K mount adapter.
What was once useless to me is now found to be even more useless.

[kypfer]

B.P.M. (Butterfield Photographic Manufacturing Co.) in the UK also made bellows with interchangeable mounts … I have mounts for PK and Praktina for mine. Other mounts are often available on eBay, but they're not cheap, and have frequently been separated into individual components, (camera mount and lens mount), so you need to check you're buying what you want


Addenda :
According to the instructions with my bellows, there was also a "Mount Connector" available "to hold any two B.P.M. interchangeable mounts back to back to enable it to be used as a short extension tube."
So, in theory at any rate, a PK to M42 adaptor was still available commercially in March '78 (publication date on instructions) … find one if you can

There's one on eBay UK at the moment BPM bellows MOUNT ADAPTER- each side takes a BPM mount | eBay … just add the mounts required and away you go! Not a cheap solution, but it'll give a wide range of adaption (with the extra appropriate mounts) so direct comparisons between lenses of different manufacturers would be feasible, if one was interested

[Kingman]

The problem with cobbling together an adapter from extension tubes is the diameters involved. Here's an Asahi Pentax M42 Auto Extension tube sitting on top (bottom?) of the PENTAX Auto Extension Tube Set K.



And given the prices that you can get for the Tube Set K after the time and effort to jury-rig something you may as well spend the extra money buy a Auto Bellows K/M/A. And that would give you the convenience of being able to stop down/open up the iris with the button on the bellows or with a cable release.

You might try some of the $5 extension tubes found on eBay. The the male/female mount parts are screwed into simple rings on some of them.

I don't think I'd trust any of my lenses to a mount held together with super glue or even epoxy

I have all the pieces and parts (M42 and K extension tubes) to cobble it together with super glue or whatever. I understand the risk with the super glue and would look for a more secure method of cobbling the pieces together. I've looked for the Pentax Bellows M and Bellows K and it seems these are much rarer than the Bellows II since their asking prices are somewhat ridiculous. That is the reason for this search for an adapter. Perhaps I will find a Bellows K at a reasonable price in the future.

[UncleVanya]

My goal was to use test out the macro usefulness of the bellows with my UWA K lenses. Reverse mounting of UWA lenses is not always possible nor would it accomplish the intended UWA Macro with a a bellow unit. Yes, I could buy a Pentax Bellows K, but I already have a Pentax Bellows II (M42) mount for the lens. Obviously adapting the new K digital bodies to the Bellows II is not an issue.

The working distance of any UWA on extensions is going to be short but here's some info that may help:
Pentax-M bellows and what makes great bellows for macro stacking photography

[TwoUptons]

I have all the pieces and parts (M42 and K extension tubes) to cobble it together with super glue or whatever. I understand the risk with the super glue and would look for a more secure method of cobbling the pieces together. I've looked for the Pentax Bellows M and Bellows K and it seems these are much rarer than the Bellows II since their asking prices are somewhat ridiculous. That is the reason for this search for an adapter. Perhaps I will find a Bellows K at a reasonable price in the future.

I found my K-mount bellows on Shop Goodwill for about $40 including shipping and some other stuff, if I remember right...

They are almost never on there, but when they are, there seem to be several...

-Eric

[Not a Number]

It's pretty much a matter of luck. I found my excellent condition Pentax Auto Bellows-A with slide copier attachment with boxes and manuals on EBay for a little over $100 with shipping. It had the dual cable release and magnification scale as well. The only thing missing were the little spools to hold film rolls.

There isn't supposed to be much difference between the K and M bellows though the K tends to run a bit lower price-wise. Functionally there isn't anything different with the A bellows but apparently the dimension on the X rail is different to the parts are not interchangeable with the K and M autobellows.