PDF (Adobe Acrobat) Documents
and other downloadable files on
Focus, Depth of Field
and other Photo Topics
Harold M. Merklinger
To view the following articles you will need to download the files and
open them with Adobe Acrobat Reader (available free from the Adobe
Web Site). The Acrobat 3 plug-in for Netscape (and some other Web Browsers)
can also be used. We continue to recommend Acrobat Reader 2.1: if nothing
else it's faster on both Mac and PC machines. This is especially important
if one has an older, slower computer.
- 4-page flyer (215k) describing The INs
and OUTS of FOCUS and FOCUSING the VIEW CAMERA.
- The Addendum to FOCUSING the VIEW CAMERA
(163k) is the last chapter of the book, written after the book's original
publication. It offers a reasonably complete version of the information
- Principles of View Camera Focus (45k) is
a brief article describing The Scheimpflug Rule, the Hinge Rule and how
they work together. This article refers to five QuickTime movies which
animate the figures in the article. The movies are not necessary to view
or print this article, but if you want to see the figures become animated,
the following five movie files must be downloaded and placed in the same
folder (directory) as the PDF file. (To see the figures become animated
you also need a copy of Apple's QuickTime. You may obtain QuickTime and
a QuickTime Movie Player for Windows in 16
bit (QuickTime 2.1 for Windows 3.1) and 32
bit form (QuickTime 3 for Windows 95) from Apple's ftp sites. For Macs
you probably only need the MoviePlayer 2.5, but I'm not sure where to get
it these days. QuickTime 3 for Mac can be downloaded here,
though registration is required. The movies themselves can be viewed independent
of Acrobat by using the MoviePlayer alone.)
Note about QuickTime: In some ways older versions (version 2.5
is good) of the Apple QuickTime Movie Player are better for viewing these
files than newer versions. The older versions let one set "play all
frames" and "loop back and forth".
is a copy of Jules Carpentier's 1901 British Patent which is referenced
in Scheimpflug's patent three years later. Carpentier's patent indicates
that what we now call the "Scheimpflug Principle" was known before
Scheimpflug's more complete work was published - in the UK, at least.
- TSBP.pdf (780k) is
a copy of Theodor Scheimpflug's 51-page British Patent of 1904. It's here
mostly for historical interest; photographers will not find it all that
useful. It describes not only what we know as the Scheimpflug Principle,
but also what I have described as the Hinge Rule and the Reciprocal Hinge
Here are a number of Portable Document Format
files containing the text and illustrations from articles originally published
Magazine. These articles are not true reprints from Shutterbug.
They contain essentially the same material but are based on the author's
original submissions, and with a few errors corrected.
- SHBG01.pdf (85k), "Adjusting Depth of
Field", Shutterbug Vol 20 No. 12, October 1991.
This article challenges some of the standard notions about depth of field.
- SHBG02.pdf (84k), "Adjusting Depth of
Field Part II", Shutterbug Vol 21 No. 7, May
1992. This item suggests it may sometimes be the best strategy simply to
focus at infinity.
- SHBG03.pdf (52k), "Adjusting Depth of
Field Part III", Shutterbug Vol 21 No. 8, June
1992. Explains how to estimate how out-of-focus an object might
- SHBG04.pdf (138k), "Adjusting Depth of
Field Part IV", Shutterbug Vol 21 No. 9, July
1992. A summary of the subject-oriented view of depth of field, and doing
it without a calculator.
- SHBG05.pdf (16k), "The Scheimpflug Principle
- Part I", Shutterbug Vol 22 No. 1, November
1992. An introduction to the well-known Scheimpflug Principle.
- SHBG06.pdf (151k), "The Scheimpflug Principle
Part II", Shutterbug Vol 22 No. 3, January 1993.
Every lens is a zoom lens: focal length may change when you tilt your lens!
- SHBG07.pdf (153k), "The Scheimpflug Principle
Part III", Shutterbug Vol 22 No. 4, February
1993. This article is really about perspective and distortion - a subject
not (yet) covered in Harold's books!
- SHBG08.pdf (150k), "The Scheimpflug Principle
Part IV", Shutterbug Vol 22 No. 5, March 1993.
The Hinge Rule and how the Hinge Rule and Scheimpflug Principle interact.
- SHBG09.pdf (122k), "Depth of Field for
View Cameras Part I", Shutterbug Vol 23 No. 1,
November 1993. How conventional depth of field works for view cameras.
- SHBG10.pdf (37k), "Depth of Field for
View Cameras Part II", Shutterbug Vol 23 No.
2, December 1993. Applying the subject-oriented depth of field philosophy
to view cameras, and how things can get so out of focus with a view camera
that they seem (mathematically) to be behind the camera!
- SHBG11.pdf (135k), "Zeiss Contaprox I
Focusing Head Outfit", Shutterbug Vol 22 No. 6, April
1993. This article describes the early 50/3.5 Zeiss Tessar in "macro"
mount and its accessories. The first "macro lens"?
- SHBG12.pdf (43k), "The Summicron 50mm
Lens", Shutterbug Vol 24 No. 8, June 1994. The first
rigid screw/M-mount 50mm Summicron from Leitz is a different - and improved
- optical formulation from that used in the collapsible lenses.
From the LHSA Viewfider:
- Kalbledr.pdf (90k), "LEANEKALB-The
Calfskin Leica: A Lesser LUXUS", LHSA Viewfinder Vol 27, No.
1, 1994. This article describes a rare version of the Leica I (A) which
has factory-applied calfskin body covering rather than the normal 'vulcanite'.
VCFaDOF2.pdf (273k) "View Camera Focus
and Depth of Field - Part II" covers depth of field for View Cameras.
Originally published in the September/October 1996 issue.
- VCFaDOF1.pdf (341k) "View Camera Focus
and Depth of Field - Part I" covers the Scheimpflug Rule and the Hinge
Rule. Originally published in the July/August 1996 issue.
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.
- ATVB.pdf (332k), "A Technical View of Bokeh,"
describes what makes the out-of-focus images different for different lenses.
Originally published in the May/June 1997 issue.
The contents of the above HTML, portable document format and movie 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.
Return to Merklinger's Photo Books: History of
Return to HM Books Table of Contents.
(20 Feb 2000 - End).