Krasnogorsk Biogon, beginners luck maybe......

Discussion in 'Adapted Lenses' started by Firefly, Jan 4, 2015.

  1. Firefly

    Firefly New to Leica Place

    Jan 3, 2015
    Cambridge UK
    Hi all, I joined the group yesterday having met Brian on another forum when I was discussing buying a Krasnogorsk Biogon, basically the forerunner of 35mm Jupiter 12 and supposedly utilising genuine Zeiss glass "liberated" from Germany about 1945 or so.
    I went ahead with it and shortly after it arrived attached it to my M8 to see how it performed conscious that they usually needed shimming to achieve a satisfactory performance. This first picture shows it was way off, a raw file taken at F2.8 from one metre, admittedly heavily cropped with added sharpening.

    original Krasnogorsk by cant_robert, on Flickr
    I had been in regular contact with Brian who kindly offered to adjust the lens if I sent it to him if I did not want to try to do so myself. My initial thought was to let Brian have it as I have never dismantled a lens in my life but looking round the site yesterday I found his posting on dismantling the Jupiter 12 and it did not look too bad so I gave it a go. Once the front element was out I found there were several shims so I left out the thinnest one and reassembled it and took a couple of seriously boring pictures to see the effect. I was amazed at the difference and emailed them to Brian for an opinion who came back with a pretty positive response.
    I went outside and snapped the back of my car again this morning using the same settings as before, this picture has been uploaded with no adjustments whatsoever other than being cropped.

    [​IMG][/url] modified Krasnogorsk by cant_robert, on Flickr[/IMG]

    It looks pretty good to me hence the beginners luck. I do really need to try it out at different apertures and distances to get the full dirt on it but at the moment the weather here in England is none too good, a more interesting subject would help as well no doubt,
    I am pretty positive about it at the moment though, regards to all, Rob :D
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  2. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    It looks great to me! The Jupiter-12 is easy to shim, easier than the J-8 and J-3. On the latter, the hard part is re-indexing the aperture ring, means moving it and drilling out 3 taps. The J-12, aperture ring stays put no matter what shim is used.

    That Zeiss glass in the Biogon is very good, you will get some great results.

    And- I made some of the project threads into "Stickies" to make them easier to find.
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