Re: Konica 120 infrared

[George L Smyth <GLSmyth@xxxxxxx>]

Willem-Jan Markerink wrote:
> 
> On  8 Sep 96 at 18:23, George L Smyth wrote:
> 
> > Willem-Jan Markerink wrote:
> > >
> > > FWIW, in this Agfa-Gevaert IR book they state that sunlight of
> > > 6000Kelvin can be split in 40% visible, 59% heat/IR, and 1% UV.
> >
> > Of course, this IR will not be recorded on film.
> 
> I know, I know, not *all* of it, but surely something!
> If it ain't visible nor UV....what else?....;-))

If you're talking about heat, the following is from an article I wrote
for Maxim Muir's newsletter (and exists on my Web page).

There are four categorizations of heat that give off infrared radiation:

     the warm range (temperatures that include the human body and the
ground on a sunny summer day), 
     the calorific range (temperatures around that of boiling water), 
     the hot-object range (nonincandescent subjects in the 250-450C
(482-842F) range), and 
     the glowing range (objects exhibiting near-red incandescence). 

All objects emit energy - the hotter the object, the greater the width
and intensity of the emitted spectrum. Objects in the glowing range
exhibit sufficient energy to display visible light with a dark-red color
and can be rendered by ordinary panchromatic film. Objects in the
hot-object range (heated soldering irons, etc.) present wavelengths that
may be recorded on infrared film. In the calorific range, the infrared
radiation is in the 1400nm and higher region, and the human body
exhibits radiation in the 9,000-13,000nm area. As it is impossible to
sensitize silver halide beyond 1,300nm, there is no way a human will
exhibit infrared radiation in a recordable range, unless, of course,
they are on fire. 

george

-- 
 Handmade Photographic Images     
  http://www2.ari.net/glsmyth

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Topic No. 13