Further Information on Focus

This site offers the following additional information on focus-related matters:

"Depth of Field Revisited" (in HTML format) provides an quick overview of the method described in The INs and OUTs of FOCUS .  

A really neat conventional depth of field calculator exists on line as Nick Sushkin's Depth of Field On-Line Plotter. This on-line calculator lets you enter the focal length and several apertures for your lens, and receive back a plot of depth of field over a range of distances. Originally Nick fixed the diameter of the circle of confusion at 1/30 mm, but he's recently updated his calculator to let the user enter any value. The formulae Nick uses are superior to what one generally finds in books; they are accurate in the close-up region without having to compensate for effective f-number!

The Acrobat Reader needed to wiew and print the the following PDF documents can be downloaded from the Adobe Web Site. We continue to recommend Acrobat Reader 2.1: if nothing else it's faster on both Mac and PC machines than Acrobat 3. This is especially important if one has an older, slower computer.

An Addendum to FOCUSING the VIEW CAMERA   describes basic information about view camera principles, especially depth of field. The PDF file FVCADNDM.pdf is about 163k in size and carries the full detail of the original printed Addendum.

A two-part article on View Camera Focus and Depth of Field appeared in VIEW CAMERA magazine in July/August and September/October 1996:

  • VCFaDOF2.pdf (273k) covers depth of field.

  • These ten articles are essentially reprints of articles on the subjects of focus, depth of field and lenses published by SHUTTERBUG    Magazine between October 1991 and December 1993:


    From Photo Techniques magazine:

  • SHSPAT.pdf (112k), "Scheimpflug's Patent", describes some of the information contained in Theodor Scheimpflug's 1904 British Patent. Originally published in the Nov/Dec 1996 issue.

    Copyright Notice

    The contents of the above portable document format files (or printed versions thereof) are copyright Harold M. Merklinger of Halifax, Nova Scotia, Canada. With appropriate attribution, either to "Harold M. Merklinger" or to "http://fox.nstn.ca/~hmmerk/", personal or not-for-profit use may be made of these materials. That is, providing individuals or organizations acknowledge the source of the information and do not charge for its use or distribution, they may copy and use the materials provided. Without the express permission of the author, the material may not be used in or included with printed or formatted-for-computer records offered for sale. Individual photographers, professional or amateur, are free to make personal use of this information in their work. Information on how to contact the author is provided at How to get these books.

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