ftp://ftp.wiley.com/public/sci_tech_med/electro-optical/howlers.txt

November 2, 2001

Howlers file for "Building Electro-Optical Systems:  Making It All Work"
by Philip C. D. Hobbs.

This file is for serious errors of fact and understanding, the sort of
thing that can lead someone astray.  Ordinary typographical errors and
minor errors of fact are corrected in the errata file,
ftp://ftp.wiley.com/public/sci_tech_med/electro-optical/errata1.txt, and
some corrected figures are in
ftp://ftp.wiley.com/public/sci_tech_med/electro-optical/fixedfig.pdf.

Any errors listed here will be fixed as far as practicable in subsequent
printings.  Really extensive changes will have to wait for another
edition.

Note that all errata are listed in order of the LAST printing in which
they occur--unless an error was introduced by trying to fix another
error, it will have been there from the beginning.  Accordingly, all
these errata should apply to the first printing, those listed in the
second printing section to the second and subsequent printings, and so
on.

I will gratefully acknowledge first finders of new howlers by name, in
print.  No error is too small to be worth fixing.  Send errata and
queries to the author at hobbs@alumni.stanford.org.  Updated versions of
these files and other supplementary material can be found at
ftp://ftp.wiley.com/public/sci_tech_med/electro-optical.

Thanks for your help.

Phil Hobbs
IBM T. J. Watson Research Center
PO Box 218
Yorktown Heights, NY 10598


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Howlers In First Printing, June 2000  (Fixed in second printing, August 2001)
************************************

Example 9.5, P. 307, third sentence and equation 9.44:


The detector's amplitude PSF (before spatial sampling) is rect(x/delta) rect
(y/delta), so since u and x/lambda are the conjugate variables, the detector
CTF is the product of two sinc functions scaled by delta/lambda.  Squaring
the rectangular amplitude PSF to get the intensity PSF doesn't change its
functional form, so the CTF is equal to the OTF, and we get

                            2
                       delta
OTF(u,v) = CTF(u,v) =  ------- sinc(u delta/lambda) sinc(v delta/lambda)
                             2
                       lambda                                            (9.44)


Howlers In Second Printing, August 2001
***************************************

Section 7.8, P. 224, third through fifth sentences sentences and Equation 7.16:

"...pretty good retroreflector if its index is close to 2.0:  for a single
interface, a ray parallel to the axis at height h has sin theta sub i = h/R.
Retroreflection requires the light to be focused on the opposite surface, so
sin theta sub r = h/ 2R, and by Snell's law,

n sub 2 = n sub 1 (h / R)/(h/ 2R) = 2 n sub 1                   (7.16)

If n sub 1 = 1, then n sub 2 must be 2, which can be done in glass.  To prevent
most of the light...."

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