Wray enlarging lens

Discussion in 'Enlarging' started by Dave Miller, Nov 23, 2005.

  1. Dave Miller

    Dave Miller Member

    Messages:
    3,894
    Joined:
    Dec 22, 2003
    Location:
    Middle Engla
    Shooter:
    Medium Format
    I have an enlarger lens which was made by Wray of London. It is marked as a 3¼in f/45 supar SER III.
    The aperture setting is engraved in the sequence: 1, 2, 4, 8, 16, 32.
    I’m interested to understand the aperture sequence, and why is the lens marked f45 when the setting only goes to 32, any ideas anyone?
     
  2. Ole

    Ole Moderator Staff Member Moderator

    Messages:
    9,281
    Joined:
    Sep 9, 2002
    Location:
    Bergen, Norw
    Shooter:
    Large Format
    Are you sure it isn't f:4.5?

    Anyway, the settings are for relative exposure. 1 second at "1" equals 2 seconds at "2" and so on.

    The Lens Collector's Vade Mecum, which tends to be good on British lenses, has this to say:
     
  3. David H. Bebbington

    David H. Bebbington Inactive

    Messages:
    2,364
    Joined:
    Dec 12, 2004
    Location:
    East Kent, U
    Shooter:
    Medium Format
    I have a similar lens - close examination with a nuclear-powered loupe reveals a decimal point between the 4 and 5.
    As Ole says, the markings are intended to indicate relative exposure requirements at the different apertures - if the markings are whole-stop steps starting at f4.5, the smallest will be f25.
     
  4. Dave Miller

    Dave Miller Member

    Messages:
    3,894
    Joined:
    Dec 22, 2003
    Location:
    Middle Engla
    Shooter:
    Medium Format
    You are right, there is a suggestion of a dot between the 4 & 5.
    Thanks for that information; I was begining to think I had an f1 lens; but it looked a bit small for that. One fine day I shall make some prints with it since it seems to be in very good condition.