DConvert
Joined: 12 Jun 2010 Posts: 921 Location: Essex UK
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Posted: Mon Sep 02, 2024 9:55 pm Post subject: |
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DConvert wrote:
I assume your lems is one of the auto only M42 types, if not switching it to M will allow the aperture to close irrespective of the pin.
Many people who buy auto only M42 lenses for adapting to digital actually end up lambing/sticking the pin in to make it manual only.
Provided it is the pin itself that's failed it should be quite easy to find something that can activate the aperture as the pin did when pushed & stick this in place permanently (I think a sanded down matchstick should do it). If this doesn't work it will be necessary to remove part of the rear of the lens, to jamd the auto mechanism on - more involved but not too involved.
These fixes will not restore the original auto operation, but will cause the aperture ring to close the iris straight away. This will be a minor disadvantage if using the lens on an auto M42 film body, but not if adapting, or on an older manual only M42 body.
I'm lucky in that all my M42 lenses are either preset or switchable models, so I can always get the apertures to operate what ever hardware I mount them on. |
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FlexiPack
Joined: 09 Jul 2008 Posts: 9 Location: Manchester, UK
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Posted: Mon Sep 02, 2024 11:03 pm Post subject: |
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FlexiPack wrote:
The lens does have a switch to manual (A or M sliding switch) but it makes no difference. Aperture still doesn't move. So, if this should bypass the pin, then does this mean the aperture blades are stuck? Ugh, that would be a much bigger issue. |
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visualopsins
Joined: 05 Mar 2009 Posts: 10950 Location: California
Expire: 2025-04-11
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Posted: Mon Sep 02, 2024 11:36 pm Post subject: |
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visualopsins wrote:
Some part of the aperture actuation is undone possibly broken.
The Complete Guide to Disassembling and Cleaning the Carl Zeiss Jena 135mm f/3.5 Lens.
https://web.archive.org/web/20130718083314/http://www.aprd31.dsl.pipex.com/articles/czj135svc/ _________________ ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮ like attracts like! ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮
Cameras: Sony ILCE-7RM2, Spotmatics II, F, and ESII, Nikon P4
Lenses:
M42 Asahi Optical Co., Takumar 1:4 f=35mm, 1:2 f=58mm (Sonnar), 1:2.4 f=58mm (Heliar), 1:2.2 f=55mm (Gaussian), 1:2.8 f=105mm (Model I), 1:2.8/105 (Model II), 1:5.6/200, Tele-Takumar 1:5.6/200, 1:6.3/300, Macro-Takumar 1:4/50, Auto-Takumar 1:2.3 f=35, 1:1.8 f=55mm, 1:2.2 f=55mm, Super-TAKUMAR 1:3.5/28 (fat), 1:2/35 (Fat), 1:1.4/50 (8-element), Super-Multi-Coated Fisheye-TAKUMAR 1:4/17, Super-Multi-Coated TAKUMAR 1:4.5/20, 1:3.5/24, 1:3.5/28, 1:2/35, 1:3.5/35, 1:1.8/85, 1:1.9/85 1:2.8/105, 1:3.5/135, 1:2.5/135 (II), 1:4/150, 1:4/200, 1:4/300, 1:4.5/500, Super-Multi-Coated Macro-TAKUMAR 1:4/50, 1:4/100, Super-Multi-Coated Bellows-TAKUMAR 1:4/100, SMC TAKUMAR 1:1.4/50, 1:1.8/55
M42 Carl Zeiss Jena Flektogon 2.4/35
Contax Carl Zeiss Vario-Sonnar T* 28-70mm F3.5-4.5
Pentax K-mount SMC PENTAX-A ZOOM 1:3.5 35~105mm, SMC PENTAX ZOOM 1:4 45~125mm
Nikon Micro-NIKKOR-P-C Auto 1:3.5 f=55mm, NIKKOR-P Auto 105mm f/2.5 Pre-AI (Sonnar), Micro-NIKKOR 105mm 1:4 AI, NIKKOR AI-S 35-135mm f/3,5-4,5
Tamron SP 17mm f/3.5 (51B), Tamron SP 17mm f/3.5 (151B), SP 500mm f/8 (55BB), SP 70-210mm f/3.5 (19AH)
Vivitar 100mm 1:2.8 MC 1:1 Macro Telephoto (Kiron)
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