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charley5
Joined: 11 Feb 2020
Posts: 353
Location: India
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 Posted: Sat Feb 12, 2022 4:34 pm Post subject: Need assistance with custom projection lens (KO-120) |
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charley5 wrote:
Hi Everyone:
I am trying to figure out a way to attach a filter to a modified projection lens, actually a hybrid of the KO-120 and an unidentified lens. The front portion of the barrel comprises the KO-120. I have had advice from a Russian fellow who said his KO-120 accepted an M72x0.75 filter size. But he later suggested that his version might have been modified (ring shaved). I have tried a 72mm step up ring and a 72mm step down ring, but neither fits on my unit. Any suggestions? Are there adapters with clamps that may be used to fit a standard filter on lenses that have uncommon thread sizes? I have attached three images of my lens. Any help would be appreciated! Thanks!
-Charles
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visualopsins
Joined: 05 Mar 2009
Posts: 11069
Location: California
Expire: 2025-04-11
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| Posted: Sat Feb 12, 2022 5:35 pm Post subject: |
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visualopsins wrote:
There are many screw-in and clamp-on filter sizes and adapters. In any case need to measure thread size and/or outside diameter. Inexpensive calipers will be accurate enough. A ruler can be accurate enough.
Click here to see on Ebay
_________________
☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮ 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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charley5
Joined: 11 Feb 2020
Posts: 353
Location: India
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| Posted: Sat Feb 12, 2022 10:45 pm Post subject: |
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charley5 wrote:
| visualopsins wrote: |
There are many screw-in and clamp-on filter sizes and adapters. In any case need to measure thread size and/or outside diameter. Inexpensive calipers will be accurate enough. A ruler can be accurate enough.
Click here to see on Ebay |
That's great. Thank you very much for the suggestions! The outside diameter is 75mm. Can you suggest where I can get the clamp on adapters? I checked around and there doesn't seem that much available.
Thanks again,
-Charles |
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visualopsins
Joined: 05 Mar 2009
Posts: 11069
Location: California
Expire: 2025-04-11
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| Posted: Sat Feb 12, 2022 11:00 pm Post subject: |
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visualopsins wrote:
Try ebay and google https://www.ebay.com/sch/i.html?kw=75mm%20clamp-on%20lens%20hood and https://www.google.com/search?q=75mm+clamp-on+lens+hood
_________________
☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮ 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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charley5
Joined: 11 Feb 2020
Posts: 353
Location: India
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| Posted: Sun Feb 13, 2022 7:21 am Post subject: |
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charley5 wrote:
Thank you so much! |
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RokkorDoctor
Joined: 27 Nov 2021
Posts: 1438
Location: Kent, UK
Expire: 2025-05-01
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| Posted: Sun Feb 13, 2022 3:13 pm Post subject: |
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RokkorDoctor wrote:
That is probably no thread you are looking at, but the anti-reflection grooves on the inside of the lens retaining ring. Sometimes that is made by cutting a (helical) thread, sometimes they are just parallel grooves.
In any case, if a filter needs only a temporary fix then a roll of black insulation tape can be your friend.
_________________
Mark
SONY A7S, A7RII + dust-sealed modded Novoflex/Fotodiox/Rayqual MD-NEX adapters
Minolta SR-1, SRT-101/303, XD7/XD11, XGM, X700
Bronica SQAi
Ricoh GX100
Minolta majority of all Rokkor SR/AR/MC/MD models made
Sigma 14mm/3.5 for SR mount
Tamron SP 60B 300mm/2.8 (Adaptall)
Samyang T-S 24mm/3.5 (Nikon mount, DIY converted to SR mount)
Schneider-Kreuznach PC-Super-Angulon 28mm/2.8 (SR mount)
Bronica PS 35/40/50/65/80/110/135/150/180/200/250mm |
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charley5
Joined: 11 Feb 2020
Posts: 353
Location: India
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| Posted: Sun Feb 13, 2022 4:12 pm Post subject: |
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charley5 wrote:
| RokkorDoctor wrote: |
That is probably no thread you are looking at, but the anti-reflection grooves on the inside of the lens retaining ring. Sometimes that is made by cutting a (helical) thread, sometimes they are just parallel grooves.
In any case, if a filter needs only a temporary fix then a roll of black insulation tape can be your friend. |
Thanks, Mark, that makes a lot of sense. I think you are right: they are anti-reflection grooves. I am looking for a more permanent solution than just with tape. I want the filter purely as a protective shield for my front element.
-Charles |
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16:9
Joined: 04 Apr 2014
Posts: 311
Location: UK
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| Posted: Mon May 30, 2022 11:22 am Post subject: |
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16:9 wrote:
In similar situations (when I've not cared about maintaining 'correctness' or resale value) I've epoxied a step-ring to the front of the housing. If your front barrel diameter is 75mm, you might try this:
https://www.ebay.co.uk/itm/153311134527
_________________
If it ain't broke, break it. |
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