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03-17-2011, 02:16 AM   #1
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Carl Zeiss Ultron 50mm/1.8 with Bayonet Mount (pics) and HELP!!!

So the LBA struck again, this time with an extra dollop of stupidity!

I got this legendary CZ Ultron (concave front element).... drum beat....


.....in the super-weird Icarex bayonet mount.

Well, on the bright side the lens seems to be in excellent nick and holding it to the K20D I tried to take some pics (all wide open at f1.8):

https://picasaweb.google.com/103430830473331312618/20110317Ultron?authkey=Gv...CuGGitbUZcD9g#


But... has anyone tried adapting these?? The registration distance is 2.5mm higher than Pentax so it should be possible in theory.

How about practice?

03-17-2011, 02:44 AM   #2
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It took a bit of searching but I found that 1) Icarex-M42 adapters *were* made, but no longer; and 2) a picture of the lens base is suggestive. It suggests that maybe a cheap Bower M42-PK adapter contact-cemented to the lens base might suffice. If that doesn't work, a little thinner will dissolve the contact cement, so no damage is done. That's where I would start. Or send me the lens and I'll see what can be done, non-destructively. No dremels, I promise!
03-17-2011, 02:52 AM   #3
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Hi RioRico.

Thanks for looking into this.

But I thought if you cement the adapter, it would sit too far away. Holding the lens flush with the K20D the round part doesn't go into the camera and with the focusing ring on infinity, the actual focusing distance is less than 2m. So this doesn't sound workable. Or am I missing something?
03-17-2011, 09:44 AM   #4
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QuoteOriginally posted by DanielT74 Quote
So this doesn't sound workable. Or am I missing something?
No, you've probably got it right. The next option would likely involve replacing the lens base, or other surgery, and I can't recommend anything there because I haven't palpated such a lens. I see that Leitax has an EOS adaptation, but not Pentax. That doesn't help.

HEY, DOES ANYBODY HERE KNOW ANYTHING ABOUT ICAREX??

03-17-2011, 11:11 AM   #5
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I think RioRico's idea of cementing an m42 adapter has merit. You just have to shim up 2.54mm from the the lens mount's face to the m42 to K adapter to retain the 48mm registration distance. The flange thickness of the genuine Pentax m42 mount is 0.7mm. The flange thickness of the third party, chrome plated m42 adapter without infinity focus is 1.66mm. The difference in an m42 adapter that can give infinity focus and those without is 0.96mm. If you use the above third party adapter, you just need to find or fabricate a washer that's 1.58mm thick that will go between your lens and the adapter. If you cannot locate a washer of this specification, get another of the same m42 adapter, grind off the locking tab portion of the adapter down to the flange level then a few passes on a 120grit sandpaper laid flat on a table should get the washer/flange down to the desired thickness.

I believe my calculations are correct but RioRico probably knows more about doing something like this than anyone else. Perhaps he can refine the adaptation process to make it more simpler.

Thanks,
03-17-2011, 04:14 PM   #6
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Thanks excanonfd!

The rear of the lens looks like this:



It is too wide to go into the K20D and not quite wide enough to attach an M42 mount I think.

Not sure how I would go about shimming it... Might be worth trying to take it off?? I will try to have a go with a handy friend of mine today (I've got two left hands... - apologies to the left-handers - you know what I mean)

Last edited by DanielT74; 03-17-2011 at 04:25 PM.
03-17-2011, 06:41 PM   #7
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Daniel,

I wouldn't know where to start with this lens. I guess the first thing is to determine where the registration distance of 48mm is on the lens. I am guessing again that it's the inner surface of the breech lock is where it starts. Wherever it is, that's where you will add 2.54mm including the m42 mount to the lens to get it to work with Pentax bodies. Does the ring with the three slotted screws remain stationary or move in and out as you focus? What is the outer diameter of the ring with the slotted screws? If the ring with the slotted screws could be removed without affecting the normal function of the lens, it might be simple to shim out the required distance with the no-infinity m42 mount, which has a diameter of 59.6mm.

Thanks,
03-17-2011, 10:06 PM   #8
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We had another look and I am guessing that you are correct in saying that the registration distance is from the inner surface of the breech lock (because like I said holding the lens flush with the mount on the K20D it doesn't even come close to infinity focus). The ring with the screws does not move, only the rear element in its housing moves. The diameter of the ring is 48mm (coincidentally?).

My friend (the handy one) is a bit apprehensive about removing the ring. We undid the screws yesterday (the were pretty short ~3mm or so) and they sit in a slot (rather than a hole?) and they are not sufficient for removing it. There are two screws on a side also..

PS Rio, thanks for offering to try to do it. The reason I haven't jumped at it yet is because the shipping is pretty high (two-way) and I am still holding onto a slim hope that we could do something here. I am not even very fussed if dremels are involved as long as the lens works properly afterwards. The bayonet mount is not incredibly useful anyway.


Last edited by DanielT74; 03-17-2011 at 11:03 PM.
03-17-2011, 11:22 PM   #9
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Any hope of using this lens on a Pentax body hinges on successful removal of the ring. A Genuine Pentax m42 adapter has an inner diameter of 42mm (obviously), outer diameter of 48.39mm. There is no way to place the m42 adapter around the ring - which would have been the ideal solution only if the ring wasn't so large.

It's always apprehensive when venturing into something like this. I am gathering my courage to tackle a CZJ 135/3.5 m42 mount (stuck aperture) when it arrives sometime in the next 10 days, and that lens has clear step by step instructions available on mflenses. Usually when I do things like this, I take it apart part of the way through and reassemble the lens, just so that I can get better familiarized and to reassure myself I can reverse the process, should I run into trouble. Anyways, without knowing what could be lurking under the ring, whether it hides some mechanism essential to the lens' function or just a cover that keeps the aperture pin properly aligned, I don't see what you can do without removing it.

Edit: I searched the mflenses.com for the Zeiss Ultron 50/1.8 Icarex, and this link poppedup: http://forum.mflenses.com/icarex-concave-zeiss-ultron-1-8-50mm-disassemble-t...%2Bicarex.html. There are not that many pictures or explanations but may be you can ask what if anything is underneath the ring and how to remove the ring.

Thanks,

Last edited by excanonfd; 03-17-2011 at 11:31 PM. Reason: found new information
03-18-2011, 03:23 AM   #10
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Oops, I forgot about AUS-USA shipping when I offered to look at it. Sorry.

QuoteOriginally posted by excanonfd Quote
Any hope of using this lens on a Pentax body hinges on successful removal of the ring.
Indeed.

QuoteQuote:
Edit: I searched the mflenses.com for the Zeiss Ultron 50/1.8 Icarex, and this link poppedup: ICAREX concave Zeiss ULTRON 1.8/50mm disassemble::Manual Focus Lenses. There are not that many pictures or explanations but may be you can ask what if anything is underneath the ring and how to remove the ring.
This looks do-able. Remove wide base, replace with flanged M42-PK adapter cemented down, while adjusting for infinity. And remove auto-aperture mechanism so lens acts as a preset. Yes, that looks like it could be done.

But the obvious question: Is it worth it? Was this 'legendary' Ultron cheap enough that if it all goes wrong, few tears will be shed? Would it be better to leave this lens alone, don't reduce its value, sell it and look for one in M42 base?

My first conversion was chopping a Nikkor 85/2 to fit a PK mount, and I was VERY nervous. I considered: It only cost me US$9. I could maybe sell it for US$100-200. But could I find a good PK or M42 replacement for that? Do I want to wait? So I dremeled, and I'm glad I did because I use that lens a lot, but I'm probably stuck with it for life.

So, with the Ultron: What is your risk-tolerance level? Can you chance ruining it?
03-18-2011, 04:09 AM   #11
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Good question, Rio.

It wasn't cheap - I stupidly thought it was M42 because the Icarex it came on had no markings (neither BM nor TM) which I later found means BM (bayonet mount). So I overpaid.

Sell it? Sounds sensible but the attraction of attempting a first is too great. On Tuesday my handy friend is going to bring some tools to work and we might attempt some surgery...

Until then if you, excanon or anyone else have more helpful tips and words of caution - we'd really appreciate that.

By the way I have a broken old Zeiss 135/3.5 with M42 mount. Might be worth taking it off and using that instead of the m42-K adapter? What do you think?
03-18-2011, 05:46 AM   #12
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QuoteOriginally posted by DanielT74 Quote
By the way I have a broken old Zeiss 135/3.5 with M42 mount. Might be worth taking it off and using that instead of the m42-K adapter? What do you think?
My Zeiss experience is slight and irrelevant. My 3 Zeiss lenses (a 4th will arrive soon) have totally different construction, totally different bases, so I don't know if what you have are similar enough that you can interchange parts. The Ultron was made in M42 also, so maybe they are compatible. Measure and see. Old carpenter's rule-of-thumb: Measure twice, cut once.

Since you've decided to operate on the Ultron, here are the issues I see:

1) Register is obvious. The difference can be finessed.
2) Aperture automation. It will go away, most likely.
3) (Ir)Reversibility. Once chopped, there is no return.

I hope your exploratory surgery goes well. Good luck!
03-18-2011, 01:02 PM   #13
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QuoteOriginally posted by DanielT74 Quote
Good question, Rio.

It wasn't cheap - I stupidly thought it was M42 because the Icarex it came on had no markings (neither BM nor TM) which I later found means BM (bayonet mount). So I overpaid.

Sell it? Sounds sensible but the attraction of attempting a first is too great. On Tuesday my handy friend is going to bring some tools to work and we might attempt some surgery...

Until then if you, excanon or anyone else have more helpful tips and words of caution - we'd really appreciate that.

By the way I have a broken old Zeiss 135/3.5 with M42 mount. Might be worth taking it off and using that instead of the m42-K adapter? What do you think?
How broken is the 135/3.5, and what would be the point of converting the Ultron Icarex into a screw mount lens, you would have to use an m42 to PK adapter to shoot with it on your Pentax dslr anyways. You should use one each of these adapters, the silver one to mount to your camera, the black one to be ground down to the desired thickness to use as a shim/washer to set the registration distance on the lens.

If the optics on the 135/3.5 is in fine condition, I would attempt to repair that too. In fact, because the repair for the 135 is well documented, attempting to repair it first before tackling the Ultron might give you and your friend some hands on experience in how to manage a lens repair. I've done a few repairs (fungus, sticky aperture, and stiff focus ring) but never a complete dismantle, I'd need a lot more courage for that!

Thanks,

Last edited by excanonfd; 06-15-2011 at 09:01 PM.
03-19-2011, 03:33 AM   #14
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Sell it on Dan, no point butchering a decent piece of glass. And do be more wary of LBA buys re compatability. A CZ Pancolar would probably have been a lot more affordable and a tad faster.
03-19-2011, 12:05 PM   #15
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Daniel,

While I was composing a reply to a different thread (Tamron Adaptall mount), it occurred to me that for Adaptall lenses to work (ie: infinity focus) with all of the different camera bodies Tamron made mounts for, it's native register distance has to be greater than the longest 35mm SLR's register distance for which an Adaptall mount was manufactured. It's certainly longer than 45.46mm because the PK Adaptall mount's flange is quite a bit thicker than the m42 mount's flange.

There are Chinese Adaptall mounts with no moving parts, with infinity focus and a massive flange to grind down to 2.54mm needed for the Icarex register distance of 48mm. If you can remove the ring around the rear element, the breech lock ring, and set them aside without damaging them, this third party Adaptall mount may be the answer to a reversible conversion to a PK mount that you desire.

Hope this helps,

Last edited by excanonfd; 06-15-2011 at 09:01 PM.
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