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Old September 26th 08, 03:02 PM posted to rec.photo.digital,rec.photo.digital.point+shoot
Don Stauffer
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Posts: 237
Default Infrared photography

DaveC wrote:
I want to photograph and video in infrared mode.

I understand that some point-and-shoot cameras provide this style of
photography/videography. Alternately, some people have "hacked" a camera by
removing the IR filter from in front of the imaging element. There are
instructions on-line to DIY this, or to send in your P&S to have it done.

Basically, the IR filter is removed and replaced with another (not a
procedure for the faint at heart). The replacement filter is $$$.

My question is this: is this replacement filter that passes rather than
blocks IR available as a gelatin or other commonly available filter that I
can source elsewhere other than from these camera-mod services?

Or can I just strip off the existing filter and not replace it with anything?
I'm looking for quantitative data (the existence of IR) not qualitative data
(a pretty picture). What function does the replacement filter provide (other
than passing IR data)?

To clarify, I want to "see" IR images real-time in the viewfinder, not
post-process the image data to reveal the IR.

If there's another forum you suggest I should ask this question in, please
let me know.

Thanks,


You will not SEE the IR regardless of whether the filter allows a live
preview.

A filter only allows or blocks a given wavelength- it does not CONVERT
it from one wavelength to another.

In effect, the digital camera does a conversion, but provides three
channels of color info. The read channel does not maintain spectral
information. All reds are the same. What the result is is a "false
color" picture. You are not viewing real infrared radiation when you
view a print or a viewfinder image taken with an IR-enabled camera.