Results 1 to 5 of 5

Thread: Shutter speeds on a Copal 1

  1. #1

    Join Date
    Feb 2008
    Posts
    111

    Shutter speeds on a Copal 1

    I have purchased a shutter speed tester recently as I am trying to make a shutter similar to the one shown in this post:
    http://www.largeformatphotography.in...ad.php?t=63707

    I have noticed on testing one particular shutter, a Copal 1 SNo. 1561xx, that the top speeds are very slow, 1/400th sec is actually 1/200th sec and 1/200 is 1/172, the rest of the slower shutter speeds are within 5% of the indicated speed. I realise that mechanical shutters will vary and not be too accurate, but I always though that the faster speeds on mechanical shutters were more accurate than the slower. The fastest speed I have used so far on this shutter is around 1/125th second.

    Should I worry and have an expensive CLA or just leave things as they are?

    Thanks in advance for your input.

    nn

  2. #2
    Octogenarian
    Join Date
    Sep 2003
    Location
    Frisco, Texas
    Posts
    3,529

    Re: Shutter speeds on a Copal 1

    If you are not using the 1/200sec. and 1/400 sec. speeds, and the slower speeds are accurate, leave things as they are.

    If you are planning on using those faster speeds, it's CLA time.

  3. #3

    Join Date
    Mar 2006
    Location
    Sullivan, IL
    Posts
    760

    Re: Shutter speeds on a Copal 1

    1/172 is within Copal's spec of 1/3 stop, isn't it? As to the highest speed, I've never seen one more than a few years old that's even close, the -1 stop is about right, from my experience. Since most of my exposures tend to 1 sec. or longer, I don't worry about it.

  4. #4

    Join Date
    Aug 2007
    Location
    Montgomery, Il. USA
    Posts
    550

    Re: Shutter speeds on a Copal 1

    Faster speeds are usually much slower than indicated and your values are typical of the beast. If you actually use faster speeds, just make note of the actual speeds to use them.
    A CLA most times will not help you out, it might, but rarely. ISO tolerance on high speeds are in the +/- 50% range so your speeds are within range.

  5. #5

    Join Date
    Dec 2006
    Location
    Chicago, IL
    Posts
    1,420

    Re: Shutter speeds on a Copal 1

    Who uses the 1/400 speed on a Copal 1? I don't even use it for strobes, because I'm worried that my flash duration is longer than that.

Similar Threads

  1. Copal shutter parts
    By svlindbe in forum Lenses & Lens Accessories
    Replies: 6
    Last Post: 25-Oct-2010, 11:16
  2. Copal 0 shutter - implication of bad slow speeds
    By walter23 in forum Lenses & Lens Accessories
    Replies: 5
    Last Post: 28-Dec-2006, 19:31

Bookmarks

Posting Permissions

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