Compares to this one:

Vivitar 28mm f2.8 MC Wide angle Lens, Pentax K fit

As long as those are not program lenses, they should fit on the K10D fine. The Ricoh program lenses have a green “P” on the aperture ring. The program lenses are the lenses that get stuck on Pentax auto-focus camera bodies. If you look at the back of the lens, the contact that would jam the lens onto the body is roughly opposite the red dot that is used to align the lens with the camera mount. If there is a contact there, the lens will am on a Pentax AF body. If these lenses are contemporary with the XR-2s body, they probably don’t have contacts and will work fine on the K10D. Just check them out.

I have the XR Rikenon 28 1:2.8 and like it a lot – though I have not used it with the K10D, only film bodies.

I didn’t talk about the Ricoh film bodies in my post, but I really like them. I had an XR-2 and it was a sweet camera – I liked it a lot. It had a lot of features that you don’t find in many bodies – like mirror pre-fire through the self timer switch, DOF preview, PC jacks for external strobes, even a lever that dropped a louvered blind over the finder, so light entering from the eyepiece would not affect the exposure reading. It’s one heck of a nice camera.

I believe the XR-2s had a solar power feature – I think that is what the “s” stands for. It also runs on batteries. You can find a complete on-line manual for this camera here:

http://www.butkus.org/chinon/ricoh/xr-2s/xr-2s.htm

Good luck!

- MCC

Thanks for your question. Let’s start with a warning – Ricoh program lenses are not compatible with Pentax auto focus bodies – either film or digital. Unless the lens is modified, it will jam on the body, requiring a trip to the repair shop to get the lens off. I know – I’ve done it! Read the “Note On Ricoh Lens Compatibility” section in the main article above. So proceed with caution and do not attempt to mount a Ricoh program lens onto any Pentax autofocus body – film or digital. If you are not sure if the lens is a program lens or not, find someone who can identify it. I believe that the program lenses have a green “P” on them, but I’m not sure that covers all the bases. So be careful!

Having said that… the Pentax DSLR’s would be an option that could allow you to use your Ricoh lenses.

There are limitations. First off, if you have program lenses you would have to remove the contact on the lens that causes it to jam on the body. I did this with a Ricoh 50mm f1.7 and it works fine on my Pentax Digital SLR bodies. Obviously, the lens will no longer work in program mode on the Ricoh cameras if this modification is made.

The second set of limitations involve the DSLR and working with a non-auto lens. This combination works, but the Pentax DSLR’s need a Pentax “A” or later lens to accurately meter with the aperture open. The cameras lacks the mechanics to read the aperture settings on older, non-auto lenses, so when you use any Ricoh lens, or older, pre-Auto Pentax lens, the newest cameras cannot engage in open aperture metering.

The solution that Pentax came up with is to use stop down metering. You put the lens on the camera, put the camera on manual mode, and set the aperture to the desired F-Stop. You then press a button on the camera and it stops down the lens, takes a light reading, and sets the shutter speed accordingly. On my *ist-D and K10D the green “hypermanual” button performs this function. To get this to work you also have to drill into the settings menu on the camera and configure it to work when the lens aperture ring is set to something other than “A”. Also – my original *ist-D required a firmware update before it could do this.

I just took a couple of quick snaps using my modified Ricoh 50mm f 1.7 lens on both my *ist-D and K 10D. Once everything was configured properly, the stop down metering worked fine. I don’t know if every Pentax DSLR model supports this – but these two do.

There are obvious limitations but it’s a work around that does let you use the older lenses, and non-Pentax K mount lenses as well. Just be very cautious regarding Ricoh program lenses, or they will get stuck on the camera.

As painful as it might be, you might want to consider just upgrading to a new camera system. The Pentax DSLR’s have a 1.5x crop factor, which means that your Ricoh lenses will work like lenses with 1.5 times the marked focal length. So, for example, on a Pentax DSLR, your 50mm lens results in an angle of view similar to a 75 mm lens on a film body. So while you may be able to use the Ricoh lenses, the range of focal lengths may no longer be as appealing. I can only speak to the Pentax brand, but the 18-55mm zoom (equivalent to a 27 – 82mm 35mm film lens) is not bad and is included in the DSLR kits for a modest increase in price over the cost of the body alone.

I hope this helps!

- MCC

I’m intersted in TC’s. But after reading your thoughts, I’m hesitant.
I have an istDS2 the DA 18-50 50-200. So far I love the range I have.

I want bigger better 300-500 ability and want to make the correct
choice. You seem to love your SMC 400 macro, and if I can source on I’d probably
get it.

Regards,

Phil B - ( pBunny )

- MCC