[baj]

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I've been thinking about getting a bellows for macro work. I found an Asahi Auto M42 bellows unit that looks pretty nice, but it only has an M42 thread on the lens end. On the camera end it looks like it has a smooth (unthreaded) hole with a set screw to hold in a piece with a lens mount to connect to the camera. Does anybody know where one could find such a part or anything else about it? Everything I've tried to google just brings me M42 to K adapters so I'm guessing this is not an easy to find item. I assume the bellows would have originally come with this piece. Any idea how to make this work that does not include glue? I am tempted to try something involving a K-mount from an old lens and a machine shop but it's probably not worth the bother. Here it is:
Asahi Pentax Screw Mount M42 Auto Bellows | eBay

[RioRico]

Got your PM. That *does* look like the rear mount piece has been removed. I have no idea where to get a replacement. If I had that bellows, I would do this: I would get a cheap thick wide-flange M39-PK adapter. (The similar wide-flange M42-PK adapters are too thin.) I would find flathead screws that fit the bellows. I would whip-out the dremel and drill counter-sunk holes in the adapter, and attach it to the bellows. Voila!

But if you're not comfortable with that, wait for an intact bellows to be listed.

[SOldBear]

You're correct. The bellows unit originally came with an "adapter" to mount the bellows to the camera. Locating the original "adapter" can be difficult.

There are several possibilities that may work:

- Use an old K-mount lens as an organ donor.

- Use a T/T2-to-K mount adapter.

- Use the adapter from this set. From this set, you may be able to get the adapter for the other end of the bellows too (to mount pK mount lens to it).

[baj]

Wow, thanks for the information! I have never handled a bellows so I wasn't sure if my interpretation of the photo was correct. I would not be opposed to the M39-K adapter route, as that does not involve glue. But it still may not be worth the effort. I'll think about it though.

SOldBear, you don't mean that a T-mount adapter would be exactly the right diameter to fit the bellows, do you? (I don't know anything about T-mount and whether or not a bellows would like use the same specifications.)

[SOldBear]

SOldBear, you don't mean that a T-mount adapter would be exactly the right diameter to fit the bellows, do you? (I don't know anything about T-mount and whether or not a bellows would like use the same specifications.)

I don't know for sure if a T-mount adapter will fit.

I may be able to check it tonight. I'll post back if I know more.

[excanonfd]

Wow, thanks for the information! I have never handled a bellows so I wasn't sure if my interpretation of the photo was correct. I would not be opposed to the M39-K adapter route, as that does not involve glue. But it still may not be worth the effort. I'll think about it though.

SOldBear, you don't mean that a T-mount adapter would be exactly the right diameter to fit the bellows, do you? (I don't know anything about T-mount and whether or not a bellows would like use the same specifications.)

SOldBear's third option of using the K mount from an el cheapo extension tube is probably the best option. It's quite beefy and lots of flange area to work with. You might even be able to transpose the screw holes from the bellows to the K mount part of the extension tube. Whether you glue, or mechanically fasten the K mount to the bellows (or combination of both), you'd better do a thorough job because your camera will be attached to it. If you think this is not worth the effort, wait for a bellows assembly that is complete and probably more costly.

[jatrax]

I would not bother with that unit, it is too much trouble unless you enjoy fixing or adapting things. If you just want a good bellows wait until a complete one comes along you will be much happier.

I did a quick search for "pentax bellows" and got 98 hits. Not all of them are bellows and some are outrageously priced but there are maybe 20 to pick from that are not too expensive.

[newarts]

Fotodiox Professional Photography Supplies and Equipment

[baj]

Thanks everybody. The attraction of these old Pentax bellows is that both ends move on the rails (so no need for macro focusing rails), which isn't true of any of the cheap new ones I've seen or even most of the old ones. And I suspect that they're nice and solid. Thanks also to excanonfd for explaining SOldBear's extension tubes -- I had missed the fact that the mount flanges are separate pieces from the tubes.

[SOldBear]

SOldBear, you don't mean that a T-mount adapter would be exactly the right diameter to fit the bellows, do you? (I don't know anything about T-mount and whether or not a bellows would like use the same specifications.)

No. I tried the T2 mount with the Pentax pK-mount bellows (similar to the M42 bellows you referred to in your post, but with pK mount). It doesn't fit.

Interestingly, the inner ring of the T2 adapter fits the bellows. If only I could attach 2 inner rings of the T2 adapter back to back together....

Note that whatever adapter you use, it has to allow a way for the camera body to be attached to the bellows without rotating. Many times something gets in the way, preventing the camera body from turning.

The attraction of these old Pentax bellows is that both ends move on the rails (so no need for macro focusing rails), which isn't true of any of the cheap new ones I've seen or even most of the old ones. And I suspect that they're nice and solid.

You're absolutely right. The Pentax bellows are very nice and solid. Before I bought a macro focusing rail (which is part of a Minolta bellows kit), I modified the Pentax rail to use it as a macro focusing rail for a while.