Page 2 of 2 FirstFirst 12
Results 11 to 13 of 13

Thread: DOF calculation

  1. #11

    DOF calculation

    For additonal reference, refer to DOF in the Technique archives (about 1/2 way down) where Ron Shaw wrote:

    An article in Photo Techniques (Mar/Apr 96) on view camera focus used this method. Basically, you tape or glue a mm scale on your bed, and then focus on the nearest object of interest, read the position on the mm scale, then focus on the farthest object of interest, and note its position on the mm scale, and then, using this focus spread (in mm), refer to a chart for optimum f stop to use, based on line pairs per mm resolution. I photocopied the chart and taped it to the back of my camera for reference. I hope this helps.

    -- Ron Shaw (shaw9@llnl.gov), August 28, 1998.

    ...and Alan Gibson did some fancy typewriter diagramming as a follow up.

    I have copies of the articles referenced by Ron and they are useful, practical, flexible and well-founded. I don't have to take my calculator out nearly as often now. --Henry

  2. #12
    Robert A. Zeichner's Avatar
    Join Date
    Feb 1999
    Location
    Southfield, Michigan
    Posts
    1,118

    DOF calculation

    The suggestion about putting a mm scale on the focusing bed and calculating the focus spread is one I have found to be extremely useful. You can first make all your adjustments of movements and then calculate the spread. The resulting answer will determine the aperture needed to achieve the desired depth of field. The reason this is a more practical method is that once a rear tilt, for example, is implemented, objects that you consider to be at infinity may no longer be optically furthest from the groundglass. With the focus spread method of DOF calculation, you simply focus on the extremes, make note of the spread, look at the table of apertures (I taped a little cheat sheet to the back of my camera bag ID tag), set my lens and make the exposure. The article in Phototechniques also has the actual formula for anyone wanting to calculate the intermediate values.

  3. #13

    DOF calculation

    One of the strength of LF camera is movement, and with it comes a complete new s et of rules for Depth of field. The convention way of plane of exact focus, with two paral lel planes of near limit and far limit definining the depth of field no long app lies. Here Scheimplug fist rule and Scheimplug Hinge rule reigns.

    Harold Merklin ger's other book"FOCUSING THE VIEWO CAMERA" has extensive formular and tables of depth of field for view camera. It is a must read for LF photographer If you are not well versed in math, you may skip the mathematical formula and go direct to the Chapter 7 Tables.

Similar Threads

  1. Bellows Extension calculation
    By Jonathan Brewer in forum Style & Technique
    Replies: 15
    Last Post: 20-Jun-2010, 14:21
  2. Depth of Field calculation in the field
    By Don Wallace in forum Style & Technique
    Replies: 15
    Last Post: 31-Oct-2004, 16:54
  3. f/stop timing and partial stop calculation
    By scott jones in forum Darkroom: Film, Processing & Printing
    Replies: 12
    Last Post: 30-Jan-2002, 12:54
  4. Superwide, light falloff and exposure calculation
    By Chris Partti in forum Style & Technique
    Replies: 8
    Last Post: 16-Aug-2000, 00:44

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
  •