Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,568   Posts: 1,573,494   Online: 667
      
Results 1 to 7 of 7
  1. #1

    Join Date
    Jan 2009
    Location
    Berlin
    Shooter
    Large Format
    Posts
    32

    Table for Distar lens

    Can anybody tell me where I can find the following table for my Distar lenses? I need one for 15 cm focal length.



    This one I got together with a Distar 3/IV lens but unfortunately parts are missing.

    Markus

  2. #2
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,394
    Images
    148
    You might look on this web-page, half way down the page there's a link to a spreadsheet that calculates DOF, but it also includes the Bellows extension factors which is what you need. Then you can calculate relative apertures etc/

    Ian

  3. #3

    Join Date
    Jun 2007
    Shooter
    Pinhole
    Posts
    21
    Thanks Ian,

    Paul

  4. #4

    Join Date
    Jul 2007
    Location
    Seoul
    Shooter
    Multi Format
    Posts
    61
    Hope this is useful, I've attached a scan.
    Attached Thumbnails Attached Thumbnails Distar.JPG  

  5. #5

    Join Date
    Jan 2009
    Location
    Berlin
    Shooter
    Large Format
    Posts
    32
    Thank you very much! That is just what I was looking for. Saves me a lot of calculating.

    Markus

  6. #6

    Join Date
    Nov 2007
    Location
    Larvik, Norway
    Shooter
    Multi Format
    Posts
    22

    Distar and proxar combined

    Here you have it all, both Distar and Proxar. I'm pretty sure you read it like this:
    Vertical column in the middle is, of course, the unaided 15cm Tessar.
    f (cm) is the resulting focal length with the supplemantary lens indicated on top of each column.
    V is the factor for the change in focal length (perhaps it stands for Verlängerungsfaktor?)
    T is the factor for calculating new exposure time with the supplementary lens. Multiply the measured time by this factor.
    Relat. Appert. is the effective apperture with supplementary lens in place, with reference to the apperture scale on the lens. Orange numbers should be avoided because of too great loss in picture sharpness. Light orange numbers are o.k. for contact prints, I guess. (That's what most users would be making with this equippement). Use white numbers for sharp pictures.

    I have only made a couple of tests with Distars and Proxars at small appertures. The results were not bad. Proxar 2 enlarged from 9x12cm to about 24x30cm was quite sharp, if not stunning.

    By the way: I enlarged the table a bit (to about 7x10cm) printed it and got it laminated. Very durable and handy to keep in my bag.
    Attached Thumbnails Attached Thumbnails Distar&Proxar tbl.jpg  

  7. #7

    Join Date
    Jan 2009
    Location
    Berlin
    Shooter
    Large Format
    Posts
    32
    Thank you very much for this interesting and helpful table.

    Markus



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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