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Karhallarn
Joined: 26 May 2009 Posts: 577
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Posted: Wed Sep 23, 2009 10:29 am Post subject: Converting M42 lenses to Nikon mount?! |
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Karhallarn wrote:
Hi guys,
Some days ago I read something about taking apart a T2-Adapter for Nikon and using the Nikon mount the replace the M42 mount on a lense. Is that truly possible?
If so, what are the drawbacks?
Can I focus to infinity with such a converted lense? Do they interfere with the mirror of my D1x?
Would really appreciate some info! _________________ www.MoWePhoto.de
Olympus OM-D e-m1 II , Olympus E-5 and NEX 5 and a lot of glas.
Instagram: https://www.instagram.com/mowephoto/?hl=de
Flickr: http://www.flickr.com/photos/25115960@N08/
500px:
https://500px.com/mowephoto |
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sichko
Joined: 20 Jun 2008 Posts: 2475 Location: South West UK
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Posted: Wed Sep 23, 2009 11:02 am Post subject: |
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sichko wrote:
You can do it with Russian "A" lenses...
http://forum.mflenses.com/some-questions-could-you-help-me-out-t20542.html
Unfortunately there are only a few. _________________ John |
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Milanos
Joined: 04 Feb 2009 Posts: 110 Location: Vlašim
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Posted: Wed Sep 23, 2009 11:04 am Post subject: |
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Milanos wrote:
I don´t think it would be that easy. The register distance different is 1,04 mm and I suppose the M42 thread is shorter than the bayonet to Nikon F. so if You would machine the lens You have to cut extra different between the two mounts dimensions. I know Meyer Optic Goerlitz has the rear part interchangeable for different mount types and the same is with Pentacons I think, but not sure if all their lenses, I would bid only on tele lenses such as Orestor, Telemegor, Orestegor and so on. |
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kuuan
Joined: 14 Jan 2008 Posts: 4569 Location: right now: Austria
Expire: 2014-12-26
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Posted: Wed Sep 23, 2009 11:37 am Post subject: |
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kuuan wrote:
Sure not easy, and I'd think it must depend on the lens, the diameter of it's back lens and if you find a Nikon mount that houses that nicely.
Otherwise I think it should be possible.
The difference in register distance is little hence it will 'almost' focus to infinity and I'd very curious if that in actual use could be enough, DoF would in most cases make objects at infinity being 'in focus' anyway. _________________ my photos on flickr: https://www.flickr.com/photos/kuuan/collections |
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sichko
Joined: 20 Jun 2008 Posts: 2475 Location: South West UK
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Posted: Wed Sep 23, 2009 1:11 pm Post subject: |
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sichko wrote:
kuuan wrote: |
The difference in register distance is little hence it will 'almost' focus to infinity.... |
Look at any lens and see how the focusing scale is expanded near the close focus end and compressed near infinity. So a small movement near infinity, either by turning the focusing ring, or by pushing the lens away from the sensor/fim plane by using too large a register, can have a dramatic effect. So on a Jupiter 11A, 4/135, for example, a 1 mm movement moves the focus from infinity to ~ 15 m. On a Nikkor 2.8/28 Ais a 1mm extension moves the focus from infinity to ~ 1m. _________________ John |
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Karhallarn
Joined: 26 May 2009 Posts: 577
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Posted: Wed Sep 23, 2009 1:49 pm Post subject: |
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Karhallarn wrote:
Thank you for all your answers and for the link to the missing thread!
So it was a dream! Ok, then I will stick to my P6 lenses and save up money for some nice german leica glas...! _________________ www.MoWePhoto.de
Olympus OM-D e-m1 II , Olympus E-5 and NEX 5 and a lot of glas.
Instagram: https://www.instagram.com/mowephoto/?hl=de
Flickr: http://www.flickr.com/photos/25115960@N08/
500px:
https://500px.com/mowephoto |
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kuuan
Joined: 14 Jan 2008 Posts: 4569 Location: right now: Austria
Expire: 2014-12-26
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Posted: Wed Sep 23, 2009 3:39 pm Post subject: |
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kuuan wrote:
sichko wrote: |
kuuan wrote: |
The difference in register distance is little hence it will 'almost' focus to infinity.... |
Look at any lens and see how the focusing scale is expanded near the close focus end and compressed near infinity. So a small movement near infinity, either by turning the focusing ring, or by pushing the lens away from the sensor/fim plane by using too large a register, can have a dramatic effect. So on a Jupiter 11A, 4/135, for example, a 1 mm movement moves the focus from infinity to ~ 15 m. On a Nikkor 2.8/28 Ais a 1mm extension moves the focus from infinity to ~ 1m. |
wow, obviously I was wrong, thank you very much for the correction John!!! _________________ my photos on flickr: https://www.flickr.com/photos/kuuan/collections |
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LucisPictor
Joined: 26 Feb 2007 Posts: 17633 Location: Oberhessen, Germany / Maidstone ('95-'96)
Expire: 2013-12-03
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Posted: Wed Sep 23, 2009 6:07 pm Post subject: |
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LucisPictor wrote:
I have converted a Jupiter-37A 3.5/135 from M42 to Nikon just by replacing the mount part. Very easy and works perfectly.
But that's a Russian "A" lens, the regular M42-glass will be problematic. _________________ Personal forum activity on pause every now and again (due to job obligations)!
Carsten, former Moderator
Things ON SALE
Carsten = "KAPCTEH" = "Karusutenu" | T-shirt?.........................My photos from Emilia: http://www.schouler.net/emilia/emilia2011.html
My gear: http://retrocameracs.wordpress.com/ausrustung/
Old list: http://forum.mflenses.com/viewtopic.php?t=65 (Not up-to-date, sorry!) | http://www.lucispictor.de | http://www.alensaweek.wordpress.com |
http://www.retrocamera.de |
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karabud
Joined: 11 Apr 2009 Posts: 843 Location: Lodz
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Posted: Wed Sep 23, 2009 6:12 pm Post subject: |
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karabud wrote:
You can screw rear lens element in helios 44-3 or 44m series. It will focus to infinity with normal m42/nikon adapter. _________________ http://www.flickr.com/photos/atheist_lenses/
old
http://www.flickr.com/photos/piotr_p/ |
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horvlas
Joined: 30 Dec 2008 Posts: 202 Location: Budapest, Hungary
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Posted: Wed Sep 23, 2009 7:45 pm Post subject: |
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horvlas wrote:
karabud wrote: |
You can screw rear lens element in helios 44-3 or 44m series. It will focus to infinity with normal m42/nikon adapter. |
How did you exactly do that? Only the rear element? Or the full optical block? If only the rear element, that not would be loose? |
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karabud
Joined: 11 Apr 2009 Posts: 843 Location: Lodz
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Posted: Wed Sep 23, 2009 8:04 pm Post subject: |
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karabud wrote:
horvlas wrote: |
How did you exactly do that? Only the rear element? Or the full optical block? If only the rear element, that not would be loose? |
Hmm i find it difficult to describe in English well.
Rear element has two small cavity?. I use screwdriver to screw this for about couple mm, but not completely. It works great with 44-3. 44m-4 thos element shakes a little. _________________ http://www.flickr.com/photos/atheist_lenses/
old
http://www.flickr.com/photos/piotr_p/ |
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sichko
Joined: 20 Jun 2008 Posts: 2475 Location: South West UK
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Posted: Wed Sep 23, 2009 8:18 pm Post subject: |
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sichko wrote:
kuuan wrote: |
sichko wrote: |
kuuan wrote: |
The difference in register distance is little hence it will 'almost' focus to infinity.... |
Look at any lens and see how the focusing scale is expanded near the close focus end and compressed near infinity. So a small movement near infinity, either by turning the focusing ring, or by pushing the lens away from the sensor/fim plane by using too large a register, can have a dramatic effect. So on a Jupiter 11A, 4/135, for example, a 1 mm movement moves the focus from infinity to ~ 15 m. On a Nikkor 2.8/28 Ais a 1mm extension moves the focus from infinity to ~ 1m. |
wow, obviously I was wrong, thank you very much for the correction John!!! |
Yes it's not intuitive. An equation (see Wikipedia for example) for a simple converging lens gives the relation between the lens-object distance (S1), the lens-image distance (S2) and the focal length (f) of the lens...
1/S1 +1/S2 = 1/f
Thus S1=(f*S2)/(S2-f)
So for our 28 mm lens focused at infinity S2=f=28 mm. If we now move the lens 1 mm further away from the image (film/sensor) plane, S2= 29 mm, and
S1=(28*29)(29-28 ) = 812 mm ~ 0.8 m which is close to the "1 m" which we esimated from the focussing scale.
Of course the lens is not a simple lens, but the approximation, that it is, works well. _________________ John |
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