Confused on Lens Mounts

columbus · Feb 20, 2008

I have an old Ricoh KR-10 and a few lenses for it (50mm, 200mm, Wide) Are these lenses outdated/brand specific? In other words, if I buy a more recent film slr or dslr, will the lenses fit?

Stratman · Feb 20, 2008

They will fit Pentax and Samsung DLRS, Ricoh used the Pentax "K" mount on their 35 MM film cameras. They will have limited functionality, but once you learn HOW to use them, they will work just fine !! One thing to look out for though, is on SOME of the more recent Ricoh lenses there was a small pin that if used on Pentax DSLRs will get stuck in the autofocus hole on the Pentax and Samsung bodies, if there is no pin, no worries !! You can easily remove the pin from what I understand, so that should ease your mind.

Found this on the net:
Incompatibility Warnings:

Avoid Ricoh P-series ("Program") lenses.

You can identify these lenses by a "P" or "(A)P" setting on the aperture ring similar to the A on the A-series Pentax. When the ring is rotated into the "P" (Program) position, it locks in place and you have to depress a small button to get the aperture ring to move again. These lenses have a small ball bearing contact on the rear flange of the lens that will pop right into the hole that holds the AF cam on Pentax autofocus bodies. The result will be that the lens gets locked tight on the body, only halfway mounted.

Early, non-P-Series Ricoh lenses should cause no problem because they have no extra electrical or mechanical contacts.

Avoid third party lenses designed specifically for the program Ricoh cameras.

Beware of third-party lenses designated "KR" or "PK-R" as they are non-Pentax-compatible Ricoh K-mount and can get stuck just like Ricoh lenses. Chinon brand, Albinar, Soligor, Kiron, Tamron, Vivitar and others made such lenses, so when looking at a third party lens, make sure it's for Pentax K-mount and not Ricoh K-mount!

Lenses designated "PK-A/R" are Pentax and Ricoh compatible, and should be safe.

If you get a Ricoh lens jammed on your camera...

If you do get a Ricoh lens stuck on your Pentax camera you can often remove it by inserting a thin feeler gauge between the lens and mount on the lower right-hand side (with the camera pointing towards you) and working it around until you get it between the flange and the offending protrusion. It can take a long time but you will usually (usually!) be able to get the lens off.
Some people are reported to have had success modifying Ricoh lenses by removing the offending protrusion to make them compatible.

columbus · Feb 20, 2008

Thank you, Stratman......one more question-will there be any field of view problems if I try to use the lenses on a dslr?

elemental · Feb 21, 2008

Here are two relevant sections from the Pentax K100D manual:

It looks like you will have no issues with a KA mount lens (with an "A" setting for aperture), and a K mount (no "A") will have metering enabled if you set it up correctly, but I am sure someone with firsthand knowledge can explain it better. Any idea what the specs are on the lenses?

I use a Pentax K100D (which should be fully compatible with your lenses, with the exception of those mentioned by Stratman) and really like it. A K100D or K10D at a good price should be fairly easy to come by these days, as they are being repaced by the K200D and K20D respectively. Any of these bodies would be a solid start for your digital setup, and will allow you to use your lenses, while brands other than Pentax and Samsung (essentially the same) will not mount your lenses.

Stratman · Feb 21, 2008

columbus said:
Thank you, Stratman......one more question-will there be any field of view problems if I try to use the lenses on a dslr?

Well, there is a 1.5 x crop factor on your camera, so the field of view with the 50 mm lens will be the same as a 75 MM lens on a 35 MM film SLR. With the 200 MM, it will be the same FOV as a 300 MM lens..

columbus · Feb 21, 2008

Stratman said:
Well, there is a 1.5 x crop factor on your camera, so the field of view with the 50 mm lens will be the same as a 75 MM lens on a 35 MM film SLR. With the 200 MM, it will be the same FOV as a 300 MM lens..

Will I be able to see this change in the viewfinder, or will I have to guess?

Stratman · Feb 21, 2008

Yes, you'll notice it just try mounting the lens on your Ricoh, look at something, then look at the same thing on your K100, you'll see the narrower FOV.