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Cj
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 23, 2006 - 09:24 pm: | 
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Hello All,
Does anybody have a site they know of--or run themselves--which discusses M42-mount bodies/lenses and their compatibility?
The above question was precipitated by my learning that my Fujica ST-605's mirror is blocked by the 50/2.8 CZJ lens. Hadn't anticipated that one...
So I'm looking, ideally, for a list of M42 SLRs which have a registration distance and mirror design that will tolerate such-and-such lenses.
I suspect, given previous posts on this forum, that K-mount adapters will also preserve the problem. I have a Pentax P3, an ME Super, and a Chinon CM-7...and It's my guess that getting an M42 adapter will allow the lens to mount, but won't allow the shutter to fire because of the mirror problem.
-CJ |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 24, 2006 - 06:11 am: |
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I don't know of one offhand, but I have encountered some compatibility issues; the late Mamiya lenses that support full aperture metering have a pin that projects rearward from the aperture ring to couple to the meter.... this pin fouls on the lens mount flange of many cameras, including any K mount with an M42 adapter in it. I'd use special caution when trying any M42 lens on a different make of camera, especially where a non-standard feature like open aperture metering is involved on either side. I hadn't been aware of the mirror interference issue that you encountered, but the mirrors in 1970s-era cameras were much larger than those in the Pentacons and Prakticas that the CZJ lenses were made for, so it's not a great shock to hear it.... |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 24, 2006 - 06:28 am: |
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As slr cameras require lenses of retro-focus design, the amount of 'back protrusion' into the mirror box was not standardised by many lens manufactures. They made sure that the lenses fit the body or models they were supposed to fit. This normally did allow the lens to fit other makes of M42 mount bodies that were EXTANT at the time of production. Unfortunately newer models, of other manufactures did not always allow mounting - as you have found out.
The Fujica ST incompatibility with CZJ lenses is well known. However although there is much available on the web, I have not found an all embracing site, detailing fitment compatibility.
It is not the registration distance that varies, it is purely the physical lens design. There have been small design quirks on the M42 mount since it was designed/patented. In the early M42 mount Edixa cameras the thread start position was located at a different point on the thread circumference. Thus the original German produced lenses for the Edixa, when fitted to Praktica or Pentax bodies had the focus datum positioned off vertical by a few degrees. Many of the pre-set lenses had two set of locating holes pre-drilled, to allow proper positioning. All my early Schacht lenses have these extra holes.
As for the K mount adapter; as K and M42 register is 45.46mm you may have problems with a M42 lens. However this could depend on the K mount body you are mounting it on.
Apart from mounting some of the pre-set M42 telephoto lenses on K mount bodies, I cannot see the point of mounting auto iris lenses via a M42/K adapter. There are plenty of very good K mount optics available very cheaply. |
CJ
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 24, 2006 - 11:11 am: |
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Thank you Rick and Glenn!
My interest in an M42-mount camera is merely to be able to use the CZJ lens at eye-level; barring a suitable body, I'm left with peering down at the finder on the Praktica FX. Moreover, I find it more difficult to deal with the left-right reversed image with the small ground glass compared to a TLR.
At some point, I'll throw up my hands and just buy that submarine superstructure-looking 'prismatic' finder and be done with it. :-) |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 24, 2006 - 12:21 pm: |
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The M42 mount is older than retrofocus lenses, so particularly in the early CZJ period they were struggling to get the shorter focal lengths into the cameras. It may well be that CZJ presets of ~50mm or less might have been designed to fit as tightly to the small mirrors as they could manage, and in these cases a larger mirror from the later, wide-angle-is-easy era could be a problem. |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 24, 2006 - 12:24 pm: |
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The Contax S and Pentacon cameras are as old (in M42) as the Prakticas and have eye level finders. Reliability can be uncertain, but it's often decent after replacing the curtains. The later Pentacons (F series) had brighter screens and auto diaphragm lenses, and the FM had a split image screen as well. These are the best users of the series. There should be no compatibility issues with any CZJ lens with one of these. |
CJ
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 24, 2006 - 04:20 pm: |
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Rick,
Yes. The Contax F and S cameras are quite appealing to me. I've looked at--and read about them--in Ivor Matanle's books, and on your site.
It seems that Contax shutters--on a RF or SLR--were not the hardiest mechanisms. Add ~50 years, and...yikes. At some point, perhaps I'll be able to afford one in fine fettle.
-CJ |
Justin Smith
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 24, 2006 - 07:41 pm: |
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CJ, I have the last version of this CZJ lens (version after the Zebra series) and it mounts on my Mamiya/Sekor 500TL with no problems. The 500TL & 1000TL's seem to go pretty cheaply on eBay.
I haven't shot with my CZJ, yet. I hope to get around to cleaning the sticky aperture blades this weekend :-) |
CJ
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 24, 2006 - 10:17 pm: |
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Justin--
Excellent. Thank you for the info! |
Berk Sirman
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, May 25, 2006 - 05:08 am: |
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One incompatibility that I observed myself but never read on any internet forum is between Pentax Spotmatic bodies, and Yashinon 50/1.7 DX. The rear group housing on the Yashinon DX is too big for the spotmaic body, and the aperture actuator hits this housing before it can push the aperture pin. This occurs if the lens is focused at infinity, or close to infinity. You need to turn the focusing ring to close focus, so that the cycle completes and the camera unlocks.
Note that there is no such problem with Yashinon DS and DS-M lenses. They have a different housing fo the rear elements. I like the DX more than the DS or DS-M, and Pentax spotmatic bodies better than Yashica bodies, so this incompatibility is unfortunate for me.
Berk |
Jan Dvorak
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, May 25, 2006 - 02:03 pm: |
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Berk,
Both SUper Takumars (1.8 and 1.4) are better lenses than the Yashinon. Get either and your problem is solved!
All the best,
Jan |
