P3D Kingslake's "Optics in Photography" - II

["Dr. George A. Themelis" <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Even though this is basically a technical book, for those interested 
in the subject, a good part of it really reads like a novel (once I 
started reading it, I could not get it off my hands) thanks to the 
author's style and also to the many interesting photographs and 
illustrations (only in chapter 1 there are 24 figures in 26 pages).

Starting from the Preface the author gives plenty of "food for 
thought", discussing what has changed from the 1951 and 1963 editions 
called "Lenses in Photography", to this 1992 edition which was renamed 
"Optics in Photography".  This is very appropriate for us stereo 
photographers, dealing with 50s and 90s equipment at the same time and 
facing this evolution in our everyday work.

The first chapter is simply titled "Perspective" and deals with the 
way lenses record images and how our eyes look at them.  I found this 
chapter to be full with thought-provoking ideas.  Reoccurring photo-3d 
discussions on wide vs. long lenses, normal lenses (why are these 
equal to the diagonal of the image?), wide-angle perspective 
distortion, and more, are explained in a simple and convincing manner. 
This chapter reminding me of how what we think as 3d concepts (like 
"stretch" in projection or in a viewer with lenses longer than the 
lenses of the camera) are really 2d concepts, only the realism of 3d 
imaging makes them stand out for us.

Chapter 2 deals with "Light Rays and Lens Aberrations".  Using plain 
geometry it derives the basic lens equation and proceeds to explain 
the various lens aberrations like chromatic aberration (maybe you know 
what "achromats" are but do you know what "apochromats" are?  How 
about "aspheric" lenses?).  This chapter helped me better understand 
viewer optics and their aberrations. 

Chapter 3, "Light Waves" discusses light polarization, interference 
(people are often asking about "Newtonís rings"), diffraction, and 
pinhole cameras.

Chapter 4, "Definition and Resolution" first discusses the measurement 
of "resolving power" and then the causes of poor image definition.  
Most people are worried about lenses.  But the following sources are 
outlined and discussed: 1) picture-taking process, 2) camera, 3) 
printing (projection, viewing), 4) film, 5) development of film.  
Imagine, the lens is just one part of the camera.  There are other 
issues there like how well is the lens aligned to the film plane or 
how flat is the film held in place.

Chapter 5 is about "Depth of Field".  This is a chapter where you need 
to derive formulas to understand it better or just accept the 
conclusions at the end.  Same for chapter 6, "The Brightness of the 
Image" that deals with exposure.

To be continued.... -- George Themelis


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