Results 1 to 3 of 3

Thread: Circle of confusion

  1. #1

    Circle of confusion

    I want to know the circle of confusion for 2 lenses:

    Speed Graphic 4x5 Graflex Optar 203mm f/7.5 Speed Graphic 4x4 Graflex Optar 135mm f/4.5

    These would allow me to calculate hyperfocal and depth of field charts.

    Any help would be appreciated.

    Terry Lorch Terr725@aol.com

  2. #2

    Circle of confusion

    The circle of confusion is not a property of the lens itself. Rather, it is a m easure of how critical you, the photographer, want to be. Hyperfocal distance ( and, by extension, depth of field) will vary depending on how large a circle of confusion you consider to be "acceptable". The less critical you are (or the s maller the print size you want to make), the larger a circle of confusion you ca n use in doing your DOF calculations.

    Kodak does put out a publication on optical formulas which includes the "standar d" COC size for different film formats. (Sorry, I don't remember what they are) . However, there is no such thing as the "correct" circle of confusion for a gi ven lens--basically, its whatever you can live with.

  3. #3

    Join Date
    Jan 1998
    Posts
    15

    Circle of confusion

    Graflex put out a reference card to carry in your equipment case that lists the circle of confusion for the Graflex 135 Optar as 0.003". The card also has a de pth of field reference for various distances at each f stop. I'd be more than h appy to scan it and e-mail it to you, if that will be of use. Regards, Rob Riel ly

Similar Threads

  1. Depth of Focus - Circle of Confusion Confusion
    By Wilbur Wong in forum Cameras & Camera Accessories
    Replies: 15
    Last Post: 21-Oct-2005, 10:36
  2. Confused about the "Circle of confusion"
    By James Phillips in forum Style & Technique
    Replies: 8
    Last Post: 9-Dec-2003, 10:30
  3. Circle of Scanner Confusion...
    By Gary Albertson in forum Digital Hardware
    Replies: 9
    Last Post: 5-Jun-2001, 19:07
  4. image circle confusion
    By Lukas Werth in forum Lenses & Lens Accessories
    Replies: 5
    Last Post: 17-Oct-2000, 05:49
  5. DOF and circle of confusion
    By Roy Feldman in forum Style & Technique
    Replies: 6
    Last Post: 31-Aug-1998, 09:40

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
  •