Mamiya C330 TLR and Zone System

Discussion in 'Medium Format Cameras and Accessories' started by Todd Barlow, Nov 15, 2004.

  1. Todd Barlow

    Todd Barlow Subscriber

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    Hi:
    If my question does not give it away I will tell you that I am new to most of this.

    I recently bought a C330 and have aquired a 55mm, 80mm and 135mm (all of them are black). I have shot some T-Max 400 test film to establish a modified ASA (Zone System approach), developed in T-Max 7 minutes at 20 degrees C.

    The results of the test for the 55mm and the 80mm indicate a modified ASA for both of ASA 800.

    Of all the reading I have done of this subject, a rating greater than the manufactuers ASA seems to be a very rare outcome.

    Your comments would be most appreciated.

    Todd
     
  2. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    Your shutters may be slow. They probably need a CLA, but meanwhile you can just apply your personal EI to them and test periodically in case they loosen up with use. Calumet makes a shutter tester that costs about $80 last I checked. It's not so important that the shutter is accurate, as long as it's consistent and you know the actual speed.
     
  3. dr bob

    dr bob Member

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    David is most probably right about your shutter speed(s). My C330f lenses are mostly right on target but from time to time I've had them cleaned and checked. I do not think it unusual for one's EI to be a stop higher than rated. However, I found TMY film to be a little tricky for Zone system use. I would suggest you try TXP or PXP. And good luck.