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05-16-2011, 01:06 PM   #1
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C/Y mount modify to K mount

How hard is it to replace or modify C/Y mount to K mount?

I found this thread:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/128552-leica-z...xperience.html

RioRico,

Could you post some photo so I can try to follow your modification?

Best regards
Hoan

05-16-2011, 01:30 PM - 1 Like   #2
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Try this link on how to do it.

http://leitax.com/zeiss-contax-lens-for-pentax-cameras.html

Kim

QuoteOriginally posted by hoanpham Quote
How hard is it to replace or modify C/Y mount to K mount?

I found this thread:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/128552-leica-z...xperience.html

RioRico,

Could you post some photo so I can try to follow your modification?

Best regards
Hoan
05-16-2011, 01:49 PM - 1 Like   #3
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QuoteOriginally posted by hoanpham Quote
How hard is it to replace or modify C/Y mount to K mount?

I found this thread:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/128552-leica-z...xperience.html

RioRico,

Could you post some photo so I can try to follow your modification?

Best regards
Hoan
I just finished one conversion myself (Distagon 28mm 2.8), using the instructions in the Leitax URL that was already posted.
The hardest part was getting the screws off as the manufacturer glued them in, so I heat up the screws with a soldering gun to help loosen them. Otherwise, everything else follows as the Leitax instructions has them.
05-16-2011, 03:47 PM - 1 Like   #4
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I did the Planar 85mm f/1.4 Leitax conversion to M42 and it was pretty easy. Like taurus9 said, it can be difficult to remove some of the screws. Someone had tried to unscrew the mount on mine, so the heads on the screws were pretty much destroyed. I had to cut them out using a Dremel tool, which made the conversion a little more kludgey than I had hoped. If you already have the lens, I would check to see that you can disassemble the lens acceptably before buying the adapter. Good luck!

Kevin


Last edited by kkado; 05-16-2011 at 03:48 PM. Reason: Grammar
05-16-2011, 03:51 PM   #5
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Thanks. I'm watching... ;-)
05-16-2011, 04:30 PM - 2 Likes   #6
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Yet again: modding C/Y and OM lenses for PK mounts

I don't have photos, but here is how I modify C/Y lenses for PK mount:

Set the lens on a table, face-down. Look at the base. You will see three bayonet flags. One flag has a notch near its counter-clockwise edge. That is what I call the "leading edge", the part that would first hit a mount lug on a PK camera. The leading edges of the flags are slightly too thick to fit under the PK mount lugs.

The solution: Make those leading edges thinner! I use a #426 metal-cutting blade on a Dremel tool. With the Dremel motor at medium speed, I make a tapered cut on the underside of each flag, the side towards the front of the lens. I taper the cut to be about 10mm long, so that the leading edge now forms a wedge that will slide in under the mount lugs.

It is not difficult to visualize the needed taper, but I had help. I have sets of very cheap PK macro tubes, which come in modular screw-together sections. One section is a PK lens mount. Before cutting, I first put a candidate lens into that macro mount section and look at which part of which flag hits which lug, and where. This is like looking at the mounting mechanism from INSIDE the camera! Many modifications and adjustments become clear when you have this view.

I have made this modification to my Yashica ML 50/1.4 and DSB 50/1.9 lenses in C/Y mount. I have similarly modified my Olympus S 50/1.8 and Vivitar-Tokina 35/1.8 lenses in OM mount.

On some lenses, including my Nikon mods, I have cut a narrow slot for the Pentax camera's locking pin to engage. I cut that slot (1mm+ wide and deep, 5 mm+ long) with the same metal-cutting Dremel blade, after it has been worn down to a fairly small diameter, maybe 10-15mm. The smaller diameter means that less of the lens base is cut, and cutting the slot is easier to control. With that slot, the lens will be locked-onto the PK base pretty securely.

I call this mod non-destructive because I haven't cut away anything serious; the lens should still work perfectly on a C/Y mount. I do NOT recommend this mod with long, heavy lenses; I don't know that the tapered flags can stand real strain. I do NOT recommend this mod for very expensive lenses; if the lens is valuable, you should spend money on the Leitax kit. I DO recommend this mod for small, not-too-costly primes that don't warrant the expense of the Leitax treatment.

I also recommend that you start with some cheap trash lens, to practice on, before cutting any lens that you care about. The mod is not difficult, but anything that's f*cked-up, STAYS f*cked-up.

Last edited by RioRico; 10-11-2011 at 12:34 AM.
05-16-2011, 09:26 PM   #7
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Thanks RioRico. I will practice first. If difficult, I send the lens to leitax.com. Adding 120 euro for each lens seems expensive, even the mount alone 60-70 euro is expensive. All depends on which lens.
05-16-2011, 09:36 PM   #8
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QuoteOriginally posted by hoanpham Quote
Thanks RioRico. I will practice first. If difficult, I send the lens to leitax.com. Adding 120 euro for each lens seems expensive, even the mount alone 60-70 euro is expensive. All depends on which lens.
A benefit of my mod: It costs almost nothing, a couple quid for the blade. But modify lenses you really want to keep, because the cut lens will probably have a lower value.

05-17-2011, 05:18 AM   #9
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QuoteOriginally posted by RioRico Quote
modify lenses you really want to keep
Would it be possible to modify the Zeiss Distagon 1.4/35mm C/Y mount?

This lens has unique bokeh, and I really want owning one.
Except for the price is too high if it is for sale.

Last edited by hoanpham; 05-17-2011 at 05:26 AM.
05-17-2011, 08:01 AM   #10
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QuoteOriginally posted by hoanpham Quote
Would it be possible to modify the Zeiss Distagon 1.4/35mm C/Y mount?
If it has a standard C/Y mount, there should be no problem, but I have never examined a Zeiss C/Y lens, so I can't be sure. And you must decide whether you want to lower its future resale value.
05-17-2011, 08:10 AM - 1 Like   #11
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I have few T* lenses in C/Y mount and after a long and painful mind debate I went out and bought an used Canon 30D instead. Mainly because:

1) I wanted to keep the lenses intact
2) Canon 30D is dirt cheap and pretty good. I got mine for $200. I figured out Leitax conversion is already $100+/lens so I can't really go wrong price wise
3) With the Canon 30D I can finally mount all my Nikkor/OM/Minolta MF lenses (with proper adapter of course) without too much worries. Not to mention that all my Pentax and M42 lenses can also be mounted on the 30D as well
05-17-2011, 08:14 AM - 1 Like   #12
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QuoteOriginally posted by hoanpham Quote
Would it be possible to modify the Zeiss Distagon 1.4/35mm C/Y mount?

This lens has unique bokeh, and I really want owning one.
Except for the price is too high if it is for sale.
For that lens, I'd go the Leitax route, but I don't see it on the list of compatible lenses (perhaps only because they're rare and expensive and he hasn't had the chance to convert one).

You can email David at Leitax and ask about a mount for that lens. He's done custom mounts for people before.
05-17-2011, 03:38 PM   #13
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QuoteOriginally posted by farfisa Quote
For that lens, I'd go the Leitax route, but I don't see it on the list of compatible lenses (perhaps only because they're rare and expensive and he hasn't had the chance to convert one).

You can email David at Leitax and ask about a mount for that lens. He's done custom mounts for people before.
Leitax does have a conversion for that lens, though only for M42. It is possible to screw on a M42 => PK adapter, and cut a small slot in the adapter mount for the locking pin. That's what I've done with my 85mm Planar and it works great. Plus with the M42 mount, you can use it on all sorts of different cameras provided that you have an adapter for it.

http://leitax.com/conversion/contax/Planar_8514/index.html

Last edited by kkado; 05-17-2011 at 03:39 PM. Reason: Forgot link
05-18-2011, 12:16 PM   #14
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Thanks a lot.

The lens I am about to buy is not a MM version, no green number.
05-18-2011, 01:50 PM   #15
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QuoteOriginally posted by kkado Quote
Leitax does have a conversion for that lens, though only for M42. It is possible to screw on a M42 => PK adapter, and cut a small slot in the adapter mount for the locking pin. That's what I've done with my 85mm Planar and it works great. Plus with the M42 mount, you can use it on all sorts of different cameras provided that you have an adapter for it.

Zeiss Contax Planar 85/1.4 M42 mount conversion
Hey kkado! Thanks for that link, and sorry to hoanpham for not noticing that earlier. I didn't see it on the regular mount page, and didn't think to look on the 85 to M42 page.

QuoteOriginally posted by hoanpham Quote
Thanks a lot.

The lens I am about to buy is not a MM version, no green number.
I still think it'd be worth sending David at Leitax an email--won't cost you anything
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