This is a general photo-DSLR question that I'd like to post to users of all systems. I used to own Olympus OM cameras back in my film days. We had both aperture and shutter rings on the lenses themselves. At the time, there were adapters available to use the lenses with the EOS system and maintain functionality of the shutter ring. Is this a viable option with today's vDSLRs? In my own case, I have a Pentax K7 and am most interested in that application, but I thought I'd throw the question out to everyone. For those who don't have an all-manual camera like the GH1 or Canons, would this give us manual control over everything but ISO?

Thoughts?

Thanks.

Unlikely to No.

I'm assuming the shutter ring on the lens was part of the leaf shutter in the lens (between lens elements). That's the only shutter ring I've seen on a lens barrel and it would be good only for one actuation and would then need to be "recocked".

The adapter for EOS bodies likely required the leaf shutter be locked open and the EOS focal plane shutter would be used.

On the Canon T1i (Rebel 500D) I have used manual aperture control with a Nikkor lens (Nikon lens to EOS adapter ring on the lens) and the camera then selected shutter and ISO. And this works fairly well.

I also use the procedure of going to Av mode, dialing desired aperture, pressing and holding the DOF prevue while unlocking and twisting the lens slightly to disengage electronic communication between lens and body. On the Canon this results in the lens remaining at the last "actuated" aperture and when you switch over to video mode the camera again selects shutter and ISO to accommodate exposure for the light coming in through the lens.

Something similar to one of the above methods may work with the Pentax but will not allow manual selection of shutter and ISO. Some degree of control may be possible with ND filters.

I have and use OM lenses on my Canon DSLR's, mostly the 55/1.2, 35/2.8 and 28/3.5. I also have a OM mount Vivitar 24/2. I also have 2 OM1's and a OM10.

OM lens _do_not_ have shutters built in. The shutter speed adjustment is on the _body_, not the lens. It just happens to be where the lens mount is on the OM1, OM2 and others. On my OM10, there is no shutter speed selector at all.

The K7 can only adapt M42 lenses. You cannot adapt OM lenses to the K-mount (not without serious lens surgery or losing infinity focus). You can use manual focus K-mount lenses as well, since they have a aperture ring.

Thanks for that response Kin. I've got an OM 50mm 1.4 and 300mm 4.5 that I'm using with my GH1 and was kind of confused as to what Trip was talking about.

I bet your 55mm 1.2 cost a lot.

I bet your 55mm 1.2 cost a lot.

Surprisingly, it didn't, only about US$125- a year ago. Since then, I've seen a few go for under $200-. The OM 50/1.2 is more highly sought after.

All the DSLR's use an electronic shutter anyway...