Re: Spectral Selectivity page

[Ed Scott <Dotted.Dog@xxxxxxxxxxxxxxxx>]

Joe,

I took a quick peek at your site earlier today and plan to go back again
later.  Many interesting images.  I plant to insert a link to your page
unless you object.  I will also be eagerly looking forward to your new
book.  

The material at our Spectral Selectivity site starts out very slowly in
a fairly basic tutorial mode, so let me point out some ideas there that
might be of interest to you.  There are two ways to select out portions
of spectrum to image with.  The conventional way that everyone currently
uses of combining film sensitivity range with colored filters to isolate
portions of spectrum.  A new method is possible in the digital domain.
Two images created with differing spectral ranges can be combined with
raster ops to achieve similar results.  This creates many new
oportunities.  For example, a scene might be shot on both Konica 750 and
HIE.  After digitizing, the Konica 750 image might be subtracted from
the HIE one to isolate the 800 to 900 nm region.

Where this really gets interesting is when you create RGB false color
images like Ektachrome IR, except with the complete flexability in the
digital imaging mode to map just about any portion of spectrum to any
one of the three RGB components.  For example, consider the Konica 750
and Kodak HIE situation previously described.  You might want to map 700
to 800 nm to blue, 800 to 900 nm to red, and the panchromatic or visual
spectrum to green.  In this case, we are talking about exposure of three
different films for a single scene - obviously this technique does not
work for all subjects.  For those where it will work, some interesting
new image opportunities open up.

As another possible example, you might shoot a single photo on Ektacrome
IR and use digital raster ops to isolate each of the three components so
as to eliminate spectrum sensitivity overlap.  The resulting images
would have a different look with enhansed color purity.  The Masking
Spectrum section of our page presents the majority of these new image
control concepts.  We will be adding new material in the future.

This concept of working with spectrum in the digital domain opens many
new doors for creative control of images.  It will be exciting to see
what talented image makers like you, can create with these new methods
for controlling imaging spectrum.  Please excuse me for the blatant
evengelism mode I am in.  I know from vast experience how difficult it
can be to sell a great idea for free.  <g>

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