[disconnekt]

I know that the Ricoh K-mount manual film lenses won't work on Pentax cameras, at least without taking the pin off first.
My question is, will a Pentax K-mount manual lenses work on a Ricoh film camera? For example, a SMC Pentax 55mm f/2 on a Sears KSX (aka Ricoh KR10).

[boriscleto]

The "Ricoh pin" does not prevent a Ricoh lens from working on a Pentax camera. It can sometimes cause a lens to become stuck (the pin catches in the AF screw drive), but most lenses made after 1985 or so will not get stuck. Ricoh lenses will not work in Tv mode on a Pentax camera that has that setting (Av only using the aperture ring).

A Pentax lens will work fine on any Ricoh camera. The P function won't be available on Ricoh cameras that have a Program mode.

[disconnekt]

The "Ricoh pin" does not prevent a Ricoh lens from working on a Pentax camera. It can sometimes cause a lens to become stuck (the pin catches in the AF screw drive), but most lenses made after 1985 or so will not get stuck. Ricoh lenses will not work in Tv mode on a Pentax camera that has that setting (Av only using the aperture ring).

A Pentax lens will work fine on any Ricoh camera. The P function won't be available on Ricoh cameras that have a Program mode.

Ah, ok. Good to know.

[pathdoc]

I know that the Ricoh K-mount manual film lenses won't work on Pentax cameras, at least without taking the pin off first.
My question is, will a Pentax K-mount manual lenses work on a Ricoh film camera? For example, a SMC Pentax 55mm f/2 on a Sears KSX (aka Ricoh KR10).

The answer to your question is, in short, yes. Ditto for Chinon, and a couple of others too I think (Cosina? Topcon?). Sears cameras and lenses are also K mount, but IIRC they are almost all rebranded Ricohs. All three went from M42 to K mount in the 70s, but when they went over to program-mode capability they diverged in the way they did it.

[stevebrot]

I know that the Ricoh K-mount manual film lenses won't work on Pentax cameras, at least without taking the pin off first.

Only the ones that have the pin and for Ricoh brand (Rikenon) that mean only the Rikenon P series with the nice green "P" on the aperture ring. The others are Rikenons are all perfectly safe.


Steve

[stevebrot]

My question is, will a Pentax K-mount manual lenses work on a Ricoh film camera?

Yes...in fact, with the exception of the aforementioned Ricoh-pinned lenses + Pentax AF bodies, all K-mount lenses with aperture rings are cross compatible with all K-mount cameras*.


Steve

* OK...there are a few issues for lenses having non-conductive bases on some recent Pentax dSLRs, but there are workarounds...

[pathdoc]

there are workarounds...

Conducting electricians' tape works a treat. I have a Vivitar 28mm/2.8 that has this problem (the camera will refuse to stop down), and that fixed it. Apply to the lens where it contacts the data pins on the mount. The other "cure" is to grind or sand down the anodised finish in the same area to bare metal, but those who have near-mint lenses they don't want to mutilate might balk at this. A $20 thrift-shop "beater"* is another matter.


* "I'm gonna rock some glass, got $20 in my pocket... "

[stevebrot]

* OK...there are a few issues for lenses having non-conductive bases on some recent Pentax dSLRs, but there are workarounds...

Conducting electricians' tape works a treat. I have a Vivitar 28mm/2.8 that has this problem (the camera will refuse to stop down), and that fixed it. Apply to the lens where it contacts the data pins on the mount. The other "cure" is to grind or sand down the anodised finish in the same area to bare metal, but those who have near-mint lenses they don't want to mutilate might balk at this. A $20 thrift-shop "beater"* is another matter...

Yep, those are the work-arounds! Whether it is a problem is another matter. Historically, lack of catch-in-focus was the main concern, but on some (all) of the recent bodies, DOF preview and stop-down metering are affected. For some reason, the body checks for continuity across the data pin for those features. Go figure...


Steve

[pathdoc]

Whether it is a problem is another matter.

but on some (all) of the recent bodies, DOF preview and stop-down metering are affected.

Yes, BIG problem, especially as the older cameras that don't have this issue slowly leave service through natural attrition and newer cameras that DO have it are introduced. I did try sandwiching a bit of aluminium foil in there when I mounted the lens, supposedly the ultimate MacGyver solution; that didn't work for me, though I accept that others have tried it with some success.

[stevebrot]

Yes, BIG problem

I guess it depends on one's mix of lenses. The impact and workarounds may be summarized:

• Lack of catch-in-focus with non-conductive bases with most (all?) consumer-line bodies going back to the K100D (IIRC)
• IIRC, lack of M-mode metering with non-conductive bases started with the K-01 and continued with the K-30/K-50, K-500, and K-3/K-3II. Ditto for lack of DOF preview with non-conductive K-mounts.
• Almost all M42 lenses and accessories are painted
• Painted base K-mount gear is pretty much limited to off-brand lenses and 3rd-party extension tubes
• Lack of catch-in-focus is a big consideration for some users of extension tubes and other close-up/macro photography. Ditto for lack of DOF preview
• For catch-in-focus, sanding or application of conductive tape/foil are the only solutions
• For M42 metering, Av mode or M-mode using DOF preview are the workarounds
• For K-mount metering, sanding or adding conductive tape/foil are solutions as is conversion to full-manual aperture

Steve

(...not severely affected, though it would have been nice to still have green button in M-mode for my M-42 stuff...)