[newarts]

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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]

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]

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]

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.

Attached Images

         

[Big Dave]

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

Dave

[MattGunn]

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]

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]

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.

[MattGunn]

I made up another K mount for Olymopus Zuiko lenses this morning, this time for a 100mm f/2.8. I found the lens in an ods and sods bin at a camera shop some time ago and for £2 I couldn't resist (now wishing I'd brought almost everything in the bin). The lens is a fair number of small scratches on the front element and the focus needed re-lubricated but it all workes smoothely now and the scratches don't appear to have too muich of a detrimental effect. All the Zuiko mounts appear to be the same so the new K mount adapter is almost identical to the one for my 35mm shift lens shown previously. Bellow is a picture of the lens and one of the first tests of the lens this afternoon. I have to say that Olympus made good glass, I will have to make another mount for the 50mm f/3.5 macro I aquired next (or just go into mass production).

[pingflood]

Very cool! I agree Olympus made some excellent glass, in fact it can be quite Zeiss-like. Have a 24/2.8, 28/3.5, 35/2 and 50/1.8 I use on my FF Canon and they are all quite good; the 35/2 lacks character as does the 28 (though they are fine performers), but the 50 and the 24 are magical. Would like to add a 21/3.5 to the stable.

[Big Dave]

Hello everyone,
Well it looks like the club is growing. I have slowed down a bit on the lens mods. I recently picked up a few Takumars off of Craigslist, which has got me started modding again. I love that 35mm PC lens conversion. Congratulations on all of the great work.

Regards, Big Dave

[Voytech]

Oh man... looks like I've gone a bit over my head with my lens purchase today. I was looking at a dresser in an antique store with the wife and as we were leaving a lady came in with a car full of stuff, but two boxes peaked my interest. So $40 later, I now have a Soligor 400mm F6.3 M42 lens and a Asanuma Auto-Zoom 80mm-250mm F4.5 O/OM mount lens. So I suppose my questions are:

A) By adapting the M42 to K adapter by drilling holes and not adding to the thickness of the flange, will I get infinity focus?

B) Any of you more talented and equipped quys willing to fabricate a mount for some $?

[kacansas03]

Oh man... looks like I've gone a bit over my head with my lens purchase today. I was looking at a dresser in an antique store with the wife and as we were leaving a lady came in with a car full of stuff, but two boxes peaked my interest. So $40 later, I now have a Soligor 400mm F6.3 M42 lens and a Asanuma Auto-Zoom 80mm-250mm F4.5 O/OM mount lens. So I suppose my questions are:

A) By adapting the M42 to K adapter by drilling holes and not adding to the thickness of the flange, will I get infinity focus?

B) Any of you more talented and equipped quys willing to fabricate a mount for some $?

All the Soligor needs is a correct M42 (Pentax thread mount) to K mount(Pentax K mount) adapter. No need for drilling holes. The Olympus mount I wish you good luck with for I have no clue how you are going to get that mounted. However I can tell you that Asanuma is a good lens. I have the M42 mount version with a K mount adapter on it which happens to have the word Soligor on it.

[Phil1]

Some might find this supplier's site useful. They make quite a few Pentax to brand X and other body adapters. Good browsing:
Leica & Pentax & Nikon | Leitax

Disclaimer: I have no connection with the link and have not yet purchased anything from them.

[Voytech]

Well, things took a different turn with the Soligor as I discovered that it has the Vivitar TX mount. I am currently bidding on a TX to K mount piece on ebay. So no M42 adapter needed.

As with the Asanuma, I'll have to still wait for help. I don't have the tools needed to drill the holes in the M42 adapter accurately.