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Pentax to Olympus lens adapter?

Ronald Gregorio , Jul 15, 1999; 09:52 a.m.

I have some K-mount lenses for Pentax and I'm thinking of buying an Olympus OM SLR kit because I'm looking for mechanical shutter, spot- metering, and mirror lock-up options. I'd like to know if there is a K-mount to Olympus mount lens adapter available. If so, what would I loose in my K-mount lenses if I mount them on the OM body?

Responses

Peter Foiles , Jul 15, 1999; 02:32 p.m.

Why is there this sudden glut of people wanting to mount brand x lenses on brand y bodies. Except for a very few specific exceptions this is always a bad idea. If you want an Olympus body get Olympus lenses. If you want to use your Pentax lenses get a Pentax body.

Joseph Albert , Jul 15, 1999; 09:15 p.m.

Here is a more specific answer:

You will lose an automatic diaphragm if you find an K -> OM adapter. You will also lose the communication of f-stop from lens to camera for open-aperture metering.

What this means is that as you stop down the aperture ring on the lens, the diaphragm will actually close right away, instead of only when you take a picture. Moreover, the camera will think the lens is wide open, so it will fool the meter in this case and you'll have to compensate.

I assume you are talking about the OM-2000 camera. This is a match-needle meter system. If you use a Pentax lens on it with adapter, you'll have to leave the lens wide open and use the shutter speed indicator to vary the exposure to line up the needle. This might be awkward since to operate the meter on this camera, you push the shutter release down part way, and the shutter speed dial is right next to the shutter release, make this an awkward, one-handed operation to try to do.

I think you'll find you want OM mount lenses.

Eric Peltier , Jul 21, 1999; 12:20 p.m.

The Pentax pz-1p has spot metering and mirror pre-fire (much like MLU), and is a bargain right now for ~$500. I picked one up just a month ago!

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