Bronica SQ Ai possible metered prism failure

Discussion in 'Medium Format Cameras and Accessories' started by wilwahabri, Aug 12, 2012.

  1. wilwahabri

    wilwahabri Member

    Messages:
    7
    Joined:
    Dec 3, 2010
    Location:
    Singapore
    Shooter:
    Multi Format
    G'day

    I have a Bronical SQ Ai on which the metereted prism (an AE prism S) is indicating and exposing way off. Bright sunny day with 100 iso film was giving f2.8 at 1/30 second with 100 ISO film. That should be around f16 at 100th under those conditions.

    The Ai uses a film speed setting dial on the film back with numerous connections to get the informatin on film speed back to the finder.

    I checked the resistance of the setting circuit at various ISO values on the terminals at the top of the film back and they are varying with ISO setting from around 380 ohms at iso 100 to above 1.5 kohms at 6400 iso so this appears to be working.

    Can anyone direct me to a technical or repair manual for this camera so I can check the operation of the entire system and pinpoint the fault, which at the moment I suspect to be the meter itself.

    New batteries make no difference to the problem.
     
  2. Paul Green

    Paul Green Member

    Messages:
    156
    Joined:
    Oct 5, 2007
    Location:
    Hampshire UK
    Shooter:
    Medium Format
    I am interested in this as well, mine has been gathering dust for sometime because of it.
     
  3. kmallick

    kmallick Subscriber

    Messages:
    140
    Joined:
    Apr 1, 2011
    Location:
    Denver, Colo
    Shooter:
    Medium Format
  4. SpunkySpine

    SpunkySpine Member

    Messages:
    37
    Joined:
    Oct 14, 2012
    Location:
    New Brunswic
    Shooter:
    Multi Format
    I realize you are looking for a repair manual for the SQ-Ai.
    Would a look at the repair manual for the ETRSi be any help? Give you some ideas or leads in the right direction?
    If so try http://www.butkus.org

    Good luck