Zuiko lens Club - Page 2

*newarts* · 01-04-2009, 05:41 PM

I recently converted an OM mount lens to a K mount. It was easy.

I removed the OM mount flange & replaced it with an m42->pentax K adapter (the kind with the flange).

I just drilled holes in the adapter to match the screw locations on the lens. Infinity focus is ok.

jah3 · 08-27-2009, 02:38 PM

I am close to negotiating a Zuiko 21/2 and is thinking of a conversion to the PK mount, any help available or should i just leave it to my repairshop guy (in-house trained by Olympus in the 60's, 70's and 80's?)?

MattGunn · 10-01-2009, 07:11 AM

I have managed to get my hands on a couple of well used but optically functional Zuiko lenses for conversion. I have the 50mm f/3.5 macro and the 35mm f/2.8 shift

. The shift lens should be really easy to convert as there is no electrical or mechanical linkage between the aperture and the camera anyway so I just need to adapt a mount. The macro will be a bit more work but shouldn't be too much of a problem. I will post picure of the conversion and the results when I have some.

MattGunn · 10-04-2009, 11:37 AM

After a productive afternoon in my shed I have made and fitted a new mount on the Zuiko Shift lens

Bellow are a few photos showing some stages of conversion.

As these lenses are quite valuable I set myself the objective of making the conversion without doing anything permanent to the lens. This meant I had to make the new mount from scratch without hacking the old one. As this lens has a pre set aperture there is no linkage between the lens and the camera and so the conversion only required a new mount.

The new mount was based on one of the cheep and easily obtainable flanged M42 mounts, which are quite accurately machined from brass. The OM mount was removed from the back of the lens and measured for copying, adding 0.5mm to the thickness to match the Pentax flange focal distance. As the flange on the M42 adapter is very thin it had to be built up to provide enough material to machine back.

The first photo shows the original OM mount, the M42 mount and the ring of 6mm brass I cut out with hole saws on the bench drill. The second photo shows the M42 mount silver soldered to the brass blank. The built up mount was centred on the lathe and machined down to the dimensions of the OM mount plus the extra 0.5mm thickness as shown in the third photo. The mounting holes were then drilled and counter bored. The finished K mount is pictured next to the OM mount in the fourth photo. The completed mount was then put on the lens and I went off to play. The last photo shows one of the first pictures from the lens taken at f/2.8.

My initial impressions are that the lens is sharp wide open but it is going to take a bit of getting used to. The lens allows an upward shift movement of about 13mm but on the GX20 this is limited to about 8mm by the built in flash housing.
I think this lens is going to be a lot of fun, especially as I try to figure out how to use the shift movement effectively. I will post more pictures as I get them.

Big Dave · 10-04-2009, 11:58 PM

Nice job. Let us see some pictures of the finished lens. Some PC correction shots would be nice too.

Dave

MattGunn · 10-05-2009, 01:47 PM

The weather was good today so I managed to get out and play with the shift lens. Bellow are a few photos I took with it. The effect is quite subtle but I think with a bit more practice it could be used quit effectively. More details of this lens can be found here: Perspective Control (PC) Lense - Zuiko Shift 35mm f/2.8

Aberystwyth University physics building taken with no perspective control:

User Photo Gallery - Architecture

And with the converging verticals corrected:

User Photo Gallery - Architecture

And with the perspective exagerated:

User Photo Gallery - Architecture

And here is a picture of the finished lens. The vertical and horizontal shift scales are clearly visible. There is a bit of a dent in the filter ring (this is the only reason I could aford it) but other than that it is pretty much imaculate.

Andrew Lang · 11-21-2009, 06:28 AM

Hey guys!

Did the conversion yesterday. easy as pie. I unscrewed the o/m mount, figured out where to drill the holes in the pentax m42/k adaptor, drilled, then countersunk, screwed the adaptor on and started shooting! took about 1hr start to finish.

MattGunn · 11-21-2009, 09:32 AM

Originally Posted by Andrew Lang

Hey guys!

Did the conversion yesterday. easy as pie. I unscrewed the o/m mount, figured out where to drill the holes in the pentax m42/k adaptor, drilled, then countersunk, screwed the adaptor on and started shooting! took about 1hr start to finish.

Well done! Did you put packing behind the mount or just put it straight on?
If done without packing I guess you can focus a good distance past infinity.