Results 1 to 8 of 8

Thread: Shutter Test Nos.

  1. #1

    Join Date
    May 2007
    Location
    New York City & Pontremoli, Italy
    Posts
    752

    Shutter Test Nos.

    I just tested a lens (Nikkor-W 300mm f/5.6) with a Calumet Shutter Tester; What is the math I need to do in order to figure out by how accurate each shutter speed is?

    These are some to the numbers I've gotten.

    Shutter Speed Test No.
    1/60 .2347
    1/30 .4031
    1/15 .7209
    1/8 .13349

    Thank you for setting me on the righteous path.

  2. #2
    Eric Woodbury
    Join Date
    Dec 2003
    Posts
    1,449

    Re: Shutter Test Nos.

    do the fraction or get google to do it. 1/60 = 0.0167, 1/30 = 0.033, 1/15 = 0.067, 1/8 = 0.125, 1/4 = 0.250, 1/2 = 0.500, 1 = 1.000

    so your 1/8 looks ok. 1/15 I think you have the decimal in the wrong place and it is okay at 0.072, 1/30, same problem and getting a little long. Same with 1/60. All fine if they are consistent. Put the numbers on a sticker on your lensboard.
    my picture blog
    ejwoodbury.blogspot.com

  3. #3
    All metric sizes to 24x30 Ole Tjugen's Avatar
    Join Date
    Mar 2002
    Location
    Norway
    Posts
    3,376

    Re: Shutter Test Nos.

    1/60 = 0.01667 sec
    1/30 = 0.03333 sec
    1/15 = 0.06667 sec
    1/8 = 0.125 sec

    I really hope you have missed out a zero on those shorter times!

  4. #4

    Join Date
    Jun 2005
    Posts
    2,478

    Re: Shutter Test Nos.

    Indeed, it is easy to miss a zero or two on the Calumet tester. A color tape put on the right place helps to see it.

  5. #5

    Join Date
    May 2007
    Location
    New York City & Pontremoli, Italy
    Posts
    752

    Re: Shutter Test Nos.

    Thank You All!

  6. #6
    Roger Thoms's Avatar
    Join Date
    Jun 2007
    Location
    San Francisco, CA, Flagstaff AZ
    Posts
    1,337

    Re: Shutter Test Nos.

    If you want to see how your reading compare to what the should be you can multiply the denominator by the reading you got. For example 1/8 = .13349. So multiply .13349 x 8 which = 1.0679. Then round that figure of to a whole number which = 1 then put it over 8 which is 1/8. Very close.

    With the 1/60 = 0.2347, take .2347 x 60 = 14.082 round off to 14 then put over 60 which is 14/60 sec. which is way off, better test again, make sure the decimal is in the right place and if still way off have the shutter serviced. This is an old carpenters trick. Useful since our stupid tapes have 1/4, 1/8, 1/16 etc. on them.

    Roger Thoms

  7. #7

    Join Date
    Sep 2003
    Location
    Harbor City, California
    Posts
    1,748

    Re: Shutter Test Nos.

    Don't worry too much about accuracy. Consistency is much more important.

  8. #8

    Join Date
    May 2007
    Location
    New York City & Pontremoli, Italy
    Posts
    752

    Re: Shutter Test Nos.

    Update: Re-tested and the shorter times are definitely off; time for a CLA.

Similar Threads

  1. Shutter Speed Check...
    By Kuzano in forum Lenses & Lens Accessories
    Replies: 8
    Last Post: 5-Feb-2009, 20:31
  2. Front Mounted Shutter for Ancient Lens
    By Gordon Moat in forum Lenses & Lens Accessories
    Replies: 7
    Last Post: 20-Dec-2008, 08:03
  3. shutter speed test
    By Joseph O'Neil in forum Lenses & Lens Accessories
    Replies: 3
    Last Post: 27-Nov-2008, 09:54
  4. Accuracy of shutter speeds, test results...
    By Bill Glickman in forum Lenses & Lens Accessories
    Replies: 9
    Last Post: 2-Mar-2000, 14:53

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
  •