Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,279   Posts: 1,534,849   Online: 724
      
Results 1 to 8 of 8
  1. #1

    Join Date
    Sep 2012
    Location
    Tampa Bay, Florida, USA
    Shooter
    Multi Format
    Posts
    68

    Advice re: circa 1937 European camera aperture markings please

    Hello all. I am acquiring a circa 1937 French manufactured 6X9 folder. Shutter speeds are 100, 50, 25, B, T. Aperture markings are [FONT=Arial][SIZE=2]25 18 12,5 9 and 6,3. It is a 105mm lens. I am acustomed to the more traditional - - - 5.6, 8, 11, 16, 22 - - - aperture markings that I have on my Zeiss 105mm 6X9. Does anybody have any insight into this different scale on the French 1937 model vs the 1951 Zeiss? I plan to shoot using sunny 16 conventions so I imagine I will just interpolate on the aperture scale. It is curious to me why the difference in the scale markings. Somebody out there in APUG land probably has some insight on this. By the way, I plan to use this vintage French camera to capture some ikonic (it's not just a Zeiss word ;-}) French landmarks during my September invasion of the continent. I also have a 1941 Argus C3 (ala Tony Vaccaro) to use while in the Normandy invasion locales.

    Thanks for all responses.

    Jim[/SIZE][/FONT]

  2. #2
    frank's Avatar
    Join Date
    Dec 2002
    Location
    Bit north of Toronto
    Shooter
    Multi Format
    Posts
    544
    Images
    2
    That is an old and discontinued aperture scale. Ive heard it called the Continental scale. I have a leitz lens like that. Just interpolate like you surmised. Other old aperture scale systems require conversion charts, but not this one.
    Last edited by frank; 07-10-2013 at 07:06 PM. Click to view previous post history.
    My blog / photo website: http://frankfoto.jimdo.com/

  3. #3
    AgX
    AgX is online now

    Join Date
    Apr 2007
    Location
    Germany
    Shooter
    Multi Format
    Posts
    8,517
    Was one invasion not enough? Do you really need to make another?

  4. #4
    IloveTLRs's Avatar
    Join Date
    May 2007
    Location
    Switzerland
    Shooter
    Multi Format
    Posts
    999
    Images
    2
    I have two pre-war Leitz lenses with non-standard aperture markings. You could have a look at this section of the Wikipedia article on F-numbers -- a "Comparative table of diaphragm numbers" which helped me.
    Those who know, shoot film

  5. #5
    Jim Jones's Avatar
    Join Date
    Jan 2006
    Location
    Rural NW Missouri
    Shooter
    4x5 Format
    Posts
    1,801
    Long ago some lens apertures were marked in full stops from the largest aperture, as in the OP's example. It may seem less logical to one who uses a variety of lenses, but makes sense enough for a one-camera photographer.

  6. #6

    Join Date
    Feb 2009
    Shooter
    Large Format
    Posts
    662
    The obsolete aperture number sequence: f/6.3, f/9, f/12.5, f/18, f/25 passes 1/3 stop less light than the modern conventional sequence f/5.6, f/8, f/11, f/16, f/22.

    Thus

    f/6.3 passes 1/3 stop less light than f/5.6

    f/9 passes 1/3 stop less light than f/8

    f/12.5 passes 1/3 stop less light than f/11

    f/18 passes 1/3 stop less light than f/16

    f/25 passes 1/3 stop less light than f/22

  7. #7
    AgX
    AgX is online now

    Join Date
    Apr 2007
    Location
    Germany
    Shooter
    Multi Format
    Posts
    8,517
    So, if one started with an odd f-stop number with the largest aperture it made sense to go on with it for the smaller ones.

    Unless exposure meters etc. got the even numbers...

  8. #8
    JPD
    JPD is offline
    JPD's Avatar
    Join Date
    Mar 2007
    Location
    Sweden
    Shooter
    Medium Format
    Posts
    767
    Quote Originally Posted by Jim Jones View Post
    Long ago some lens apertures were marked in full stops from the largest aperture, as in the OP's example.
    This is not the case here. It's a normal and typical european aperture scale from that period. It's the same scale as the modern, just different numbers.

    There's no need to interpolate on it, since the shutter speeds are slower. If your exposure meter says aperture 8 and 1/125 use aperture 9 and 1/100 sec.
    J. Patric Dahlén



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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