Re: Maiden Voyage

[George L Smyth <GLSmyth@xxxxxxx>]

Don Campbell wrote:
> 
> It was also interesting to read that IR film dose not record by heat but by light.Everything that I have read or heard says that it is recorded by heat?
> 
> Upon reflection I guess it would be hard to record a distant landscape on a small film if it was only by heat.Why is it said that it is heat that records on the film?

With only a very peripheral understanding of the recording of infrared radiation, it
isn't too difficult to completely misunderstand the subject, i.e. a little knowledge
is dangerous.  Anyone thinking that body heat can be recorded would be hard pressed
to understand why loading the camera doesn't fog the film (handling the film would
transfer the heat).  Continuing this thought, one would think that it would be
impossible to use this film on a warm summer day.  Myths blindly passed along
seemingly live forever.

Infrared film CAN record heat.  The deal, however, is that the heat must be very
hot.  Kodak HIE/HSI can record a soldering iron in the dark.  To save bandwidth here,
I will direct you to "Rethinking Infrared Photography - Dispelling Myths" on my Web
page.

Some of the misunderstanding is assisted by the fact that heat CAN be recorded.  This
is called electronic thermography.  This is not photography, but a rendering of the
infrared radiation by a super-cooled photodetector onto magnetic tape (or other
recording device).  A good explanation of this can be gooten for free by asking Kodak
(800-242-2424) for publication P-570, "Thermal Recording and Infrared Photography of
Hot Objects."

> That book seems to have stirred up a bit of a hornets nests.Looks like most don't agree with the ladies techniques but like her prints.My comment is.If it works why worry.

Well, the reason is that it doesn't work.  If she is perpetuating the myth that body
heat is recorded on IR film then one will spend a frightful amount of time trying to
do just this.  It doesn't work and as long as we use silver halide as a recording
mechanism, never will (again, for the reason I will reference the above mentioned
article).

The result of properly understanding the subject is, among other things,
repeatability.  If I want to duplicate the image "Rest Gently"
(http://www2.ari.net/glsmyth/north.htm) and think that heat is causing the halo on
the head of the statue, then I will waste a great deal of time trying to duplicate
this feature.  Understanding why this happens allows one to either use it or to
ensure that it does not happen.  IMO, knowledge is the difference between a
snapshooter and a photographer (the difference between "I'll give you a copy of the
print if it turns out" and "I'll give you a copy of the print WHEN it turns out").

george

- -- 
 Handmade Photographic Images     
  http://www2.ari.net/glsmyth/
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End of Infrared-Digest V0 #281
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