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04-20-2012, 10:30 AM   #16
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QuoteOriginally posted by Vasyl Quote
I am thinking about the other Yashinon Color 45mm 1/1.7 from yashica Electro G 35. Its flange distance is 29mm.
See some link on conversion of such lens to mirrorless.
Ah, one of those. I've tried something similar, stripping a Rokkor 45/2.8 from an Ansco Autoset RF. (Same model that John Glenn carried into orbit.) The lens can only close-focus on PK mount. I've put interchangeable RF lenses with 35mm register onto PK successfully, but a 29mm register is just too short. Makes me want a Nex, eh?

QuoteOriginally posted by Medium FormatPro Quote
Trying to pose a tactful question... Would it be worth it to try to rehab the back of that particular lens that is shown? I would almost be sweating about chips from the back of the lens metal coating from going into the back of the lens - or worse - into the body of the camera.
If paranoid, I'd go over the metalwork with a steel-bristle brush, then coat it with shellac and let it dry thoroughly. That should take care of any loose bits.

04-20-2012, 02:41 PM   #17
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QuoteOriginally posted by RioRico Quote
Ah, one of those. I've tried something similar, stripping a Rokkor 45/2.8 from an Ansco Autoset RF. (Same model that John Glenn carried into orbit.) The lens can only close-focus on PK mount. I've put interchangeable RF lenses with 35mm register onto PK successfully, but a 29mm register is just too short. Makes me want a Nex, eh?.
With the recent Mr. Bunell's announcement, your desire should become stronger...:
04-20-2012, 03:17 PM   #18
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QuoteOriginally posted by Vasyl Quote
QuoteOriginally posted by RioRico:
Makes me want a Nex, eh?.
With the recent Mr. Bunell's announcement, your desire should become stronger...:
Yah, all I need is money. And more masochism. Why masochism? Because with a Nex, I'll no longer have have the "I can't mount the lens on PK" excuse any more, and I'd never sell ANY of my lenses, and I'd buy MORE and MORE, and my shelves would overflow even further, and I'd start worrying about LBA. Ay yi yi.

And the money thing... I'm thinking of starting a General Talk thread about my situation. I'm sitting in limbo. I could make money by eBaying or Marketplacing some stuff. But all the stuff I want to sell is at my home base, 1/3 of the way across the USA, and I won't be returning there until an indeterminate time in the future, maybe a month or more or less. So I have to sit here and watch deals blow by, including used Nexes. I'm too old and slow to rob minimarts so I'll just have to wait and stew. Grrr...
04-20-2012, 05:39 PM - 1 Like   #19
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It looks like your case needs attention...and serious attention...
You are almost at the edge...
As we say (translation from Russian)...money is not so important, the most important is its amount...:-)

Regarding your lens stock...I think the problem is, you need a bigger house...:-)

By the way, how about this...at least you could've put 3 lenses from your stock on k5...:-)

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04-20-2012, 07:08 PM   #20
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QuoteOriginally posted by Vasyl Quote
It looks like your case needs attention...and serious attention...
You are almost at the edge...
I've been over the edge for awhile now. When store clerks ask if I need help, I always say that I'm beyond help.

QuoteQuote:
As we say (translation from Russian)...money is not so important, the most important is its amount...:-)


QuoteQuote:
Regarding your lens stock...I think the problem is, you need a bigger house...:-)
They certainly won't fit in the house I'm in now, the 810ft^2 / 73m^2 historic adobe we've almost just sold.

QuoteQuote:
By the way, how about this...at least you could've put 3 lenses from your stock on k5...:-)
Oh yeah baby, that's what I want!
04-24-2012, 12:34 PM   #21
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Focal 135mm 1;2.8

Well...I did it...pictures are below...
Was it worth of the efforts and the money?
depends.
For me it was the first experience to convert any old lens into K-mount...I faced with some issues which definetily were worth of thinking about on finding a solution.
What I faced with was as following:
1. The lens came in a bad shape (fungus inside the rear element started to eat the coating) - was eliminated by the hydrogen peroxide solution (as long as it had eaten the coating, some uncoated spots left on the lens element), so the coating was removed - of course now pictures are blurry at wide open...
2. I had some extra K-mount ring, so I targetted to convert the lens into K-mount - it was important to find the right flange distance which would allowed to take shots at close distance and at infinity. I managed to do it, by sacrificing a couple of feet to the close focusing. Original distance was 2.1 meter (7 feet), now it is about 2.3-2.5 feet. Can improve it, but do not see a reason. At infinity it works fine.
3. Picture quality. Comparable to my Vivitar MC 135mm 1:2.8. As far as I removed the coating from the inner element, now Vivitar is much sharper wide open, but the new-old lens is 2-3 times lighter in terms of its weight.



































Last edited by Vasyl; 04-24-2012 at 03:42 PM. Reason: correcting typos
04-24-2012, 01:39 PM   #22
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more pictures:












Last edited by Vasyl; 04-24-2012 at 03:38 PM.
04-24-2012, 07:44 PM   #23
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Looks like it's quite usable. Congrats! Now you can move on to modding N/AI, OM, C/Y, Petri, etc. Have fun!

04-25-2012, 08:48 AM   #24
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Thank you RioRico.
To be honest I do not want to find myself in the situation similar to yours...:-) when I need money and space...

Will try to play with Yashica G and its Yashinon 45 mm 1/1.7, and that wll be the end...

Thanks again for your advices not only by this post but the others too. I found them all extremely useful!
06-01-2012, 08:19 AM   #25
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Interesting reading guys, I myself am now having a similar “problem” I bought myself a Pentacon 4/200 with an EXA-mount (My LBA took me by surprise). The solution as described by RioRico is not an option in this case I think since it seems to be a rather bulky lens. (lying in front of the mailbox in anticipation). Have been on the search for an adapter but couldn’t find one yet, of course I started looking way later than I purchased the lens. I had seen this lens and it was so cheap that I just could not let it pas by, want to see what 15 aperture blades can do, that is if I can somehow mount it on my Pentax.
So my questions are:
1: Do adapters exist for EXA-mount - PK-mount?
2: If not, are there solutions like the one described here before but suited for a heavier lens?
06-01-2012, 01:52 PM   #26
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QuoteOriginally posted by skien68 Quote
1: Do adapters exist for EXA-mount - PK-mount?
I haven't seen any. If they exist, they will need optical elements to reach infinity focus. Some NIF (no infinity focus) solution could be kludged by epoxying or screwing simple adapters together. I have a bellows with removable Exakta mounts. I could screw the EXA female to a wide-flange M42-PK -- that might push my Exakta-mount Kilfitt Makro Kilal E 40/3/5 (1:2) to almost 1:1!

QuoteQuote:
2: If not, are there solutions like the one described here before but suited for a heavier lens?
Does your Pentacon have a tripod socket, to use as a support point? Probably not. A support point could be improvised with a radiator-hose clamp or something similar. Then run a strong bracket from the camera base to underneath the lens support point. Insert a tube or bolt between the bracket and the support point. Now the lens' weight is supported by the bracket, not by the lens threads.

Hmmm, I have another idea. If infinity focus isn't needed, are cheap thick wide-flange M39-PK adapters. One could be epoxied around the Exakta-mount bayonet blades. That should adequately support the lens' weight. With a 200mm lens, far-focus will probably drop to around 40-50m. (I just did a rough test to get that estimate.) With the lens stopped-down to f/11-f/16, DOF might approach infinity.
06-01-2012, 03:08 PM   #27
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thanks, will see what I can do when the lens is delivered. I'll find a solution and if I do and it's something repeatable I'll post it. So now I'll just have to wait.
06-02-2012, 08:20 AM   #28
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Skien,
I guess the exa mount/ring can be unscrewed from the lens body, at least it was so in my case.
If you can unscrew the exa mount ring then it will be easy to play with to either convert into K-mount or M42.
Good luck!
06-02-2012, 08:24 AM   #29
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I recently bought 5 Star 500mm in Minolta mount.
I removed the Minolta mount ring from the lens (unscrewed) and used the the K-mount ring. So now I have 2 lenses (Focal and 500mm) which work perfectly with the K-mount adapter (described in this thread).
06-02-2012, 10:04 AM   #30
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QuoteOriginally posted by Vasyl Quote
I guess the exa mount/ring can be unscrewed from the lens body, at least it was so in my case.
If you can unscrew the exa mount ring then it will be easy to play with to either convert into K-mount or M42.
QuoteOriginally posted by Vasyl Quote
I recently bought 5 Star 500mm in Minolta mount.
I removed the Minolta mount ring from the lens (unscrewed) and used the the K-mount ring.
Some lenses can indeed have their bases fairly easily removed and replaced. Alas, I have yet to find those in Exakta and Minolta mounts. I remain alert.

Cheap hardware I keep on hand for lens mods and adaptations includes:

* Thin M39-M42 rings
* Thin-flange M42-PK adapters
* Wide-flange M42-PK and M39-PK adapters
* M42 and PK and other macro tube sets
* M42 and PK body caps (thick ones)
* bits from scavenged cameras

Ah, scavenged cameras. I've sacrificed a couple RFs for parts. Dismembering them isn't easy, at least not the Petri and Yashica RFs that have fallen prey to my savagery. And their lenses|registers are too short for anything but macros on PK cameras.

Old MF folders and boxes and Polaroids are much easier. Many of these are 75mm or longer. If they're 90mm or longer and their shutter mechanism isn't too fat, they can be mounted on most bellows. But not 75-80-85mm goodies, not if I want infinity focus.

Solution: an M42 16-35mm focusing helicoid, cost around US$60 shipped. For the lens, kludge some sort of 42mm mount, either an M39-M42 ring or an M42 body cap. I've also tried de-glassing a macro-focusing screw-on adapter, but it doesn't work nearly as well as a helicoid.

Last edited by RioRico; 06-02-2012 at 10:28 AM.
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