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10-06-2007, 01:58 PM   #1
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Ricoh XR Rikenon lenses with K-mount

Back in high school, I took a b&w photography class and shot with a Ricoh XR-10. While in the attic, I found the box I stored everything in, and low and behold my small collection of manual lenses was inside. I didn't know these Ricoh lenses were K mounts. I'd say the best out of the bunch is a Rikenon 70-150mm f/4 macro and a 28mm f/2.8.

Talk about a blast from the past. I picked up the body and looked through the viewfinder and the split focusing screen brought back a feeling of nostalgia.

I have a split screen for the k10d, which I was going to sell, but now I think I might just install it.

10-06-2007, 08:33 PM   #2
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Ricoh was a big partner of Pentax's back in the day and even 'borrowed' a few of their lenses. They have screwmount and then adopted Pentax's K Mount. Unfortunately, Pentax didn't licence their KA Mount to Ricoh so Ricoh made a seperate pin for aperture info and so you had the Ricoh "P" Lens. After that, the written record seems to die off.

Its too bad Ricoh eventually discontinued their SLR line. I think it was because of the AF moment but Ricoh would have been a strong ally of Pentax had it received continued support of the KA and subsequent KMount generations and survived to present day.

I have the Ricoh XR 28/3.5 and its a real beauty to use. Also have the XR 50 and 135. Glad to here your rediscovery! Hope you get some really good pics!
10-07-2007, 03:30 AM   #3
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I believe that some of the Ricoh lenses can jam on the current Pentax/Samsung cameras, the lens goes on ok but doesn't come off very easily. If I recall correctly it is a pin on the Ricoh that gets caught in one of the screw heads in the Pentax mount (or something like that !). If it happens the trick is to use something like a razor blade to help the pin get out of the hole.
10-07-2007, 03:41 AM   #4
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Yes I think it is the pin that allows the Ricoh lens to communicate apature information to Ricoh bodies, it can get caught in the autofocus screw. Rather than using a razor blade or something just put the focus lever into manual mode which will retract the screw. Or for a permenant solution use a dremel or something and just grind off the pin, unless you are planning on using the lens of a Ricoh body it won't effect the working of the lens at all.

Also like some non-Pentax K-mount lenses the one Ricoh lens that I own had a larger flange by the apature lever than most pentax lenses, it was almost 90 degrees long (rather than just the length of the travel of the lever) the flange ran into the mirror box on my body preventing it from mounting.....the Dremel solved that problem as well.

10-07-2007, 12:53 PM   #5
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Yea this split in Pentax KA/R (Ricoh) mount had alot of third party lenses include both systems.

If your lens gets stuck, set the camera to AF. That pushes up the AF slot screw and is usually enough to push the Ricoh Pin out of the AF slot and you can can the lens off. Sometimes it take a little wiggle.

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