Results 1 to 4 of 4

Thread: Dagor differences

  1. #1

    Join Date
    Dec 2001
    San Joaquin Valley, California

    Dagor differences

    I'm curious as to the differences between the f6.8 and f7.7 dagors. The f7.7 versions seem to be in longer focal lengths, often are said to have greater coverage, and are usually more costly---but why? Is the difference in the design of the f7.7? Is it a justifiably more desireable version of this legendary lens? I asked this question on that other forum but I thought the more savvy optical gurus over here might provide a more detailed answer. Thanks for any and all info.-------cheers!
    I steal time at 1/125th of a second, so I don't consider my photography to be Fine Art as much as it is petty larceny.
    I'm not OCD. I'm CDO which is alphabetically correct.

  2. #2

    Join Date
    Sep 2003
    South Carolina

    Dagor differences

    There is no difference in design between the f/6.8 and f/7.7 Dagors. Basically Dagors of 12" and less are f/6.8, 14" and longer Dagors are f/7.7. The slower speed of the longer Dagors apparently had as its purpose keeping the weight down.

    This answer assumes that we are comparing Dagors of the same period and manufacturer. The fact is that Dagors were made for almost 100 years and distributed under the name of many lens manufacturers (Goerz, Zeiss, Ross, Schneider, Goerz America, etc.) and there are definitely some minor design differences.
    For discussion and information about carbon transfer please visit the carbon group at

  3. #3

    Join Date
    Sep 2003
    Harbor City, California

    Dagor differences

    Sandy King gave you an excellent answer. All I would add is that shutter size and availability is a major factor in deciding a maximum aperture. This is even more a factor now than when the Dagor's were being made.

  4. #4

    Dagor differences

    Another reason for the slower speed is the size of the chunks of glass needed to make the lens. The method of making optical glass at the time Dagors was to melt the glass in a pot and break it up after it had annealed. Pieces large enough for very large lenses were rare. Nonetheless, some f/4.5 lenses were made in quite long focal lengths. Even a 12" f/4.5 Tessar is an impressive chunk of glass and some lenses were available in considerably longer FLs

Similar Threads

  1. Lense Differences
    By A Brown in forum Lenses & Lens Accessories
    Replies: 8
    Last Post: 25-May-2005, 10:33
  2. older DAGOR and coated AM DAGOR
    By qiutaolee in forum Cameras & Camera Accessories
    Replies: 4
    Last Post: 2-Nov-2004, 14:30
  3. Lens differences
    By Brent in forum Lenses & Lens Accessories
    Replies: 5
    Last Post: 28-Sep-2004, 11:42
  4. Differences between Sinar F and F1
    By Paulo Ogino in forum Cameras & Camera Accessories
    Replies: 2
    Last Post: 17-Aug-2001, 17:06
  5. Sinar F / F1 differences
    By Mike Mahoney in forum Cameras & Camera Accessories
    Replies: 2
    Last Post: 8-Apr-2001, 06:41


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts