rehess Loc: South Bend, Indiana, USA

Questions have been asked about the "Ricoh pin" and how it affects modern Pentax users. I am posting the information I have here, in this separate topic, in the hope that it can be found and referenced separately from other discussions.

Today, Ricoh owns Pentax, but "back in the day", Ricoh sometimes used the K-mount that Pentax had created. For their purposes - my understanding is this had to do with communicating aperture information between body and lens - Ricoh added a pin to their lenses. Normally this pin is retracted, and barely noticeable, but it is spring-loaded, so it can pop out "on its own". When these lenses were built, this was not a problem - no one was using that part of the mount for anything else anyway - but as they evolved the K-mount, Pentax engineers put the "screw drive" connector, connecting the lens to the body autofocus motor, in that very spot. If the pin does happen to pop out, it can catch in the connector {which is partially recessed, so pin can lodge there}, and the infamous problem has occurred.

I had to use an old image of the lens here, because I removed the pin from my lens. That job is straight-forward as described at
http://www.theatreofnoise.com/2008/05/ricoh-lenses-on-pentax-cameras-ricoh.html

The images below, repurposed from my library show the relationship between pin and connector.
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Orange circle marks inconspicuous {brass} "Ricoh pin" on lens; note that it is almost directly across from red indexing circle


Modern K-mount. Orange circle marks "screw drive"connector, making lens AF motor available to lens; note that it is almost directly across from red indexing mark ... in other words, this is where the pin will line up

Soul Dr. Loc: Beautiful Shenandoah Valley

Thanks for pointing this out. I do have some Ricoh SLRs and some of their lens. I will have to check them out before using them on my Pentax DSLR.

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

Funny thing. Ricoh now owns Pentax...

jerryc41 Loc: Catskill Mts of NY

And here I thought you meant a nice lapel pin. If Ricoh had them, I thought maybe Nikon would, too.

royden Loc: Decatur, GA

The Ricoh pin could be use as a nose stud. Sterilization is recommended. Seriously though, it's easy to remove. I've done a few.

rehess Loc: South Bend, Indiana, USA

Having been a Canon user until 27 months ago, my personal experience is that Pentax users are much more focused on old lenses. Sometimes we lose track of the fact that "any lens on any camera" applies to Pentax equipment only. I discovered that even many Pentax users are at best vaguely aware of this problem, so putting the facts down here seemed like a good idea.

jerryc41 Loc: Catskill Mts of NY

Here we are - Nikon pins.

http://www.nikon.com/100th/pin_collection