[interested_observer]

There is also a website that provides all the information for converting Olympus, Contax and Leica lenses for mounting on Pentax camera bodies:

• Olympus OM lens for Pentax cameras
• Zeiss Contax lens for Pentax cameras
• Leica & Pentax & Nikon | Leitax

I have converted one Contax CZ 28mm f2.8 to a K mount and it turned out perfect.

[cyclone3d]

Bringing this thread back to life as I just picked up an Olympus 55mm 1.2 lens.


I think I am probably going to go the way of using one of the cheap M42 to K adapters that has the lip on it. I have used the same adapter to convert a Minolta 58mm 1.4 lens, which is a much bigger chore than the Olympus lenses are.


With that said, I did find a place that sells replacement body mounts that are made to work with Olympus, Contax, Konica , Nikon, and 4/3's lenses.


Too pricy for me, and it also takes away some of the weatherproofing on a weatherproof camera.


Pentax K+ Multi-Mount (WR version) - Adaptist


Pentax K+ Multi-Mount - Adaptist

[cyclone3d]

Well, got the initial conversion done. May still have a bit to do if infinity focus is not correct. From what I can tell, at inifinity focus the helicoid is bottoming out on something, so no more adjustment is possible.


From what I can tell, at the 2ft setting, it is in focus at around 20" from the front element, which gives me about the correct distance to the focus marker on the camera.


I will test tomorrow to verify. Hoping I do not have to do any more modification to the lens.


I'll post pics once I have a chance. This looks to be a really sweet lens though.

[yucatanPentax]

Very curious to see pics of the change and the process!

[cyclone3d]

So I picked this lens up for $42.50 shipped. At some point it was dropped and the aperture adjustment ring was bent towards the body making it very hard to turn. I tapped it with a hammer next to the bend and it reshaped it enough to be useable. I may actually take it apart at some point to fix it properly, but don't want to chance messing it up.

Ok, so here are some pics of the finished (for now) lens. I may redo the conversion at some point with a brass instead of aluminum adapter. Just depends on how the aluminum adapter hold up.

The lens was also missing the grip so I took one off of an old scrap Vivitar 35-70mm 1:3.5-4.8 lens. It is almost the perfect size except for it being a tiny bit wider than the original. It works just fine how it is though, so no worries.


You can kinda tell in this pic where the ring was dented - the shiny spots.


I lined up the adapter so it would mount in the same position as it would have by default.


Now for the conversion explanation.

Initial prep
1. I removed the mount from the lens and proceeded to cut off the original bayonet with my dremel tool and a cut-off wheel.
2. I then ground off most of what was left of the bayonet with a 4" grinder.
3. Then I finished it off with the dremel tool.
4. After that, I hand sanded it and the M42-K adapter with 400 grit sand paper
5. Next the original mount was installed back on the lens.

M42-K adapter modification - Note. If I did this again, it would be in a different order.
1. I lined up the adapter where it needed to be and used a sharpy to mark where I needed to file the threads off of the adapter so the levers and original lock release would clear.
2. Then I filed, tested, and filed again, repeating until it looked like I had enough clearance for everything to move freely.
3. Then I marked the M42-K adapter where I needed to drill the holes so the modified mount can still be removed if need be.
4. I then drilled the holes and then filed the lock hole so it looked like everything would work.

M42-K adapter and original mount joining.
I used JB Weld ClearWeld to join the two parts together.
It is super easy to use, super strong, and is really thin before it starts to set.
I let it dry for about 2 hours before starting the next step.

Mounting the modified mount.
1. I did a test screw fit and found that I needed to make the holes a big bigger, mostly because they didn't line up exactly, so I pulled out the dremel again and used a diamond bit to fix the holes.
2. After I got all the screws to go into the holes, I tried to mount it and found out that I needed to take some more metal off for everything to clear.
3. Once I got everything to clear, I busted out some Testor flat black model paint and painted the M42 mount where I had filed it. I let that dry for a while.. probably about an hour.
4. I then installed the mount and found that the screw hole that was right next to/part of the lock hole for the mount was was allowing the lens to rotate quite a bit because it was way too big.
5. After trying a couple different things (glue and small bits of plastic) to try to make the hole the right size I gave up.
6. I then decided to just fill in the hole with some JB Weld Clearweld and then use a dremel diamond bit to remake the mount lock hole. This worked out great.

Aperture operation.
I wanted the lens to look mostly stock and I also wanted to be able to have full light when composing no matter what f-stop I was going to use so I left the DOF preview button in a functional state instead of jamming the aperture control in the closed position.
So when I am shooting, it always gives f1.2 unless I depress the DOF preview button. It works great like this. The DOF preview button ended up being right where the lens lock release on the camera body is.

[Jean Poitiers]

So I picked this lens up for $42.50 shipped. ... The DOF preview button ended up being right where the lens lock release on the camera body is.

Thanks for this write up. I was wondering where the grip came from J

[One3rdEV]

Cross posted with the 300mm Plus lens thread. An example taken with the OM Zuiko 300mm F4.5 multicoated film era lens. At one point of time I was thinking of selling it, but found that they were only valued at $60 USD at that point of time and so I didn't feel it was worth while. Now I'd like an opportunity to use it for a while at least.

I still plan to someday purchase infinity focus capable adapters for my two Olympus film era lenses:
1) OM Zuiko 50mm F3.5 Macro (an excellent performer)
2) OM Zuiko 300mm F4.5 (sample shown below).

Example image was taken with the lens braced against a wall, and the Pentax K5 camera mount was pressed onto the Olympus mount by hand. The image was processed using Adobe's LightRoom 'Auto' feature:

Full image


Equivalent crop per LightRoom 1:1

[uttam.hathi]

ever seen this
Olympus OM lens for Pentax cameras
cant afford leitax look for chinese alternative if available