Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,691   Posts: 1,548,912   Online: 791
      
Results 1 to 7 of 7
  1. #1

    Join Date
    Aug 2014
    Shooter
    Medium Format
    Posts
    5

    Mounting Schneider/Nikkor/Bronica lenses in Mamiya Press-helicoid?

    Hi all - new to the forums. I originally posted this in the Mamiya Super 23 flickr group, but got no response, maybe someone here has any experience?:

    I found a very interesting topic on photo.net about adapting Bronica (and other lens elements) to the Mamiya press helicoid, as they are designed for a standard copal 0 shutter.

    http://photo.net/medium-format-photography-forum/00Vh6C

    I also found this example of an Schneider 150mm Xenar 5.6 lens, inserted into a Mamiya 150mm:

    http://www.rockycameras.com/nice-sch...99-36742-p.asp

    And this with a Schneider Xenar 4.5:

    http://www.rockycameras.com/nice-sch...99-36743-p.asp

    I understand that you lose rangefinder focusing with the modifications described on photo.net (Bronica lenses), but does the same apply to these Schneider adaptions? Does anyone know how much work this requires, and have any experience with it?

    Could I mount e.g. this multicoated Nikon 150mm 5.6 in an Mamiya 150mm mount, or is the throat of the focusing helicoid too narrow? Even if lose rangefinder focusing, I still think it could be useful with an updated lens for landscapes e.g., without having to invest in a full 4x5 setup.

    http://www.ebay.com/itm/Nikon-nikkor...item19f01e8f1a

    Thanks for any suggestions!

  2. #2
    ic-racer's Avatar
    Join Date
    Feb 2007
    Location
    Midwest USA
    Shooter
    Multi Format
    Posts
    6,236
    What is the reason to do this? Mamiya lenses too hard to find?

  3. #3

    Join Date
    Aug 2014
    Shooter
    Medium Format
    Posts
    5
    No, there are plenty lenses on the used market. I bought a 150mm (old type from the 1960s) on ebay, but the shutter is not working. I considered trying to repair it, but came to the conclusion I might as well try to upgrade both shutter and lens, if it is feasible.

  4. #4

    Join Date
    Apr 2004
    Location
    Montgomery, Il/USA
    Shooter
    Multi Format
    Posts
    5,115
    I did a similar thing using a Graflex XL board. In an attempt to fabricate a more compact Camera.
    HA! I'd like to say it's an ongoing project but the ongoing part seems to have lapsed due to lack of interest on my part.
    Heavily sedated for your protection.

  5. #5

    Join Date
    Aug 2014
    Shooter
    Medium Format
    Posts
    5
    Hmm... I considered Graflex XL lenses too. For now I managed to remove the retaining nut from the back of the lens using two screwdrivers. The Polaroid 600 SE repair manual suggest a special lens spanner, but fortunately it wasn't neccessary. The lens and shutter then falls out easily from the helicoid, just unscrew the PC-cord connector.

    A few measurements of the 150mm helicoid - these are approximations, I just used some cheap calipers:

    Minimum focal flange distance, from film to inner point of lense mount flange at infinity ~ 142 mm

    Maximum focal flange distance, at closest focus distance of helicoid ~ 161mm

    This can be adjusted with extension rings, which add about 20mm or 40mm each.

    Outer diametre of back element of 150mm lens ~ 29mm

    Diametre helicoid opening behind flange ~ 45 mm(guesstimate).

    I just ordered a Schneider Xenar 150mm f5.6, as it should fit (as can be seen from the photos linked above). From the measurements it seems also e.g. a Schneider Symmar-S 150mm 5.6 should work, if my measurements are correct (back element outer diametre 40,5mm), however the APO Symmar will probably not (back element diametre 46mm). My goal is to achieve rangefinder focusing with the Xenar. I guess it should be possible by shimming the lens... I will let you know how it goes.

    Here is the helicoid with the lens removed:
    Click image for larger version. 

Name:	_DSC9989.jpg 
Views:	9 
Size:	71.8 KB 
ID:	92550Click image for larger version. 

Name:	_DSC9991.jpg 
Views:	10 
Size:	67.0 KB 
ID:	92551
    Last edited by dag.bb; 08-10-2014 at 04:33 AM. Click to view previous post history. Reason: Added images

  6. #6

    Join Date
    Aug 2014
    Shooter
    Medium Format
    Posts
    5

    It arrived!

    And here it is. I tried mounting the Xenar directly to the helicoid (like in the pictures from "Rocky Cameras" linked above), however the focus was clearly off compared to the Mamiya 150mm silver type. After adding the locknut which came with the lens to the front of the flange, it -almost- has the same focus point as the original lens, which I guess means rangefinder focusing could be possible. It also means the bare helicoid has a flange distance of less than 142,6 mm (Xenar). My guess would be about 140mm? I just need to find some shims to calibrate it a bit more. I'm checking focus using a 15 megapixel 500d with some macro rings and a pentax 645 adapter (!), so I might be too critical. At f8 it is almost perfect. Now I just need a graflok mount and graflok 4x5 back to test
    Click image for larger version. 

Name:	_DSC0031.jpg 
Views:	18 
Size:	215.9 KB 
ID:	92735Click image for larger version. 

Name:	_DSC0033.jpg 
Views:	14 
Size:	193.2 KB 
ID:	92736

  7. #7

    Join Date
    Aug 2014
    Shooter
    Medium Format
    Posts
    5
    I might be spamming the thread, but I hope this is useful for others also. Maybe I posted in the wrong location - if so mods might want to move it to Camera Modifications. Anyway... I just received a Schneider Symmar S MC (multicoated), which has a back lens diameter of 40,5mm, and it fits the Mamiya 150mm helicoid with a millimeter to spare. You need to remove a small black metal ring/tube (which can be done by hand), see the picture below, and then there is about 1mm wiggle room (marked by red in the picture), but it works! Pretty cool to have a 1990s lens on a 1960s camera! I will try to calibrate it for the rangefinder, and also check sharpness vs. the Mamiya "blue dot" 150mm. Unfortunately the APO Symmar has a back lens diameter of about 46mm, and will not fit without enlarging the throat further.

    Click image for larger version. 

Name:	_DSC0112.jpg 
Views:	5 
Size:	87.6 KB 
ID:	93525Click image for larger version. 

Name:	_DSC0115.jpg 
Views:	4 
Size:	28.2 KB 
ID:	93526Click image for larger version. 

Name:	_DSC0113.jpg 
Views:	7 
Size:	112.8 KB 
ID:	93527



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin