So I read about the 'new' Thambar-M 90mm lens and...

Discussion in 'Leica M Camera Forum' started by rflove, Nov 8, 2017.

  1. rflove

    rflove Leica Place Regular Subscribing Member

    199
    Jul 13, 2014
    A bit of fun with a nifty 50 Nikon f1.4 adapted to the M240 (and a bit of old school trickery)

    L1008603. L1008606-Edit-Edit. L1008608-Edit. L1008609-Edit. L1008611-Edit.
     
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  2. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    Nikkor 5cm F1.4- I like it!

    I saw the images from the Thambar.... I'm thinking of making a soft focus lens... It's difficult to make a sharp lens. Not so difficult to make a soft lens.
     
  3. rflove

    rflove Leica Place Regular Subscribing Member

    199
    Jul 13, 2014
    Well yes, there are lots of nifty 50's out there and definitely the sharpness falls off rapidly as the aperture increases. Definitely they aren't Summilux 50mm f1.4
    I have several old legacy lenses of various brands. With adapters they can be used with the M240 but they won't match decent glass.

    OTOH, sharpness is no requisite for making good or even great images. I like what saw of the Thambar after I had a chance to absorb it and understand the purpose of it.
    But I definitely would not rush out and buy one unless I suddenly find the jackpot lottery winning ticket laying in the street... LOL! However, I would love to shoot with the
    Noctilux f.95.....
     
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  4. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    What I'm thinking of playing around with- taking a "beyond hope" "90-Ish" telephoto and replacing the front section with a single element lens of the matching focal length.
    I've made RF-coupled single element lenses for people before- much the same idea as a soft-focus lens.
     
  5. rflove

    rflove Leica Place Regular Subscribing Member

    199
    Jul 13, 2014
    I'm not sure I quite understand. Are you suggesting a lens repair? What happens when you replace a multi element section with a single element lens? Sorry for the questions, but I'm not cognizant in these things. I've watched some YouTube videos, I think of "the angry photographer" where he discussed multi element vs single element lenses but frankly I can't remember the salient points. He's quite verbose and it's hard to keep track of the subject.
     
  6. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    Not a repair, which would mean replacing an element or group with one that is compatible with the original design. I've repaired a Zeiss 5cm F1.5 that was missing the rear triplet with one from an early Jupiter-3 that was missing the front element.

    Most complex lenses consist of front and rear sections, each is an achromat with it's own focal length. Using the "Lens Makers formula" the two sections are separated by some distance to give the overall focal length of the lens. I'm thinking of replacing one of the sections with a single element lens, of similar focal length of the section being replaced, then separating by the correct distance to match the original focal length of the lens. In this manner, the "hacked lens" maintains RF coupling. I've had some success doing this with a Nikkor 10.5cm F2.5 that was missing the rear element, and made an RF coupled lens out of a Canon 50/1.5 with the rear triplet of a Nikkor 5cm F1.4. Neither was complete when bought.

    Canikkor 5cm F1.5- wide-open,

    33248244762_4aca1cbb1f_o. Canikkor 50/1.5 by fiftyonepointsix, on Flickr

    Hacked Nikkor 10.5cm F2.5, wide-open on the M9

    8640911653_1ee3f9f327_o. Nikkor 10.5cm F2.5, hacked by fiftyonepointsix, on Flickr

    On the 10.5cm F2.5- note how the tree branch seems to cast a shadow on the Bokeh Ball. Sometimes you get very interesting effects on these lenses.
     
    Last edited: Nov 9, 2017
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  7. rflove

    rflove Leica Place Regular Subscribing Member

    199
    Jul 13, 2014
    Interesting results for sure. The one thing I miss from the "adapted" lenses is the RF coupling. At one point I would have considered playing with lenses like you do. But now my condo is just not conducive to taking up these hobbies. Space is at a premium :)....
     
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  8. Christilou

    Christilou Leica Place Veteran

    402
    Apr 5, 2013
    My view is with theses soft focus lenses is that you can soften an image easily..... sharp is much harder!
     
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  9. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    It is easy to soften an image- I was just remembering today that I wrote my first image processing subroutine in 1979- and it was a smoothing function.

    But I have great fun in "randomly combining optics" to get unanticipated side-effects.
     
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  10. rflove

    rflove Leica Place Regular Subscribing Member

    199
    Jul 13, 2014
    What I like about playing with the lenses is that one can combine a soft/somewhat sharp center with completely blurred background, and the flares from the lights are pretty cool too.. Of course, I play a little with some presets as well.