Re: [Phys-L] Crows in IR

["Prof. Keith S. Taber" <kst24@cam.ac.uk>]

Is this the kind of thing you are looking for?

   https://www.alamy.com/the-crow-infrared-scanning-the-animals-body-temperature-with-a-thermal-imager-image417147504.html

   https://www.alamy.com/black-crow-carrion-crow-corvus-corone-in-scientific-high-tech-thermal-imager-on-night-background-image397197007.html

   https://www.alamy.com/indian-jungle-crow-portrait-scanning-the-animals-body-temperature-with-a-thermal-imager-image452502674.html

   https://www.alamy.com/crow-on-the-beach-scanning-the-animals-body-temperature-with-a-thermal-imager-image411317994.html

Keith


On 17/07/2025 07:40, bernard cleyet via Phys-l wrote:
> > On 2020/Aug/09, at 14:45, John Sohl via Phys-l<phys-l@mail.phys-l.org>  wrote:
> >
> >
> > Just because a crow (or anything) is black in visible light, doesn't mean
> > it is a blackbody in IR (or UV). I tried to do a net search for an IR photo
> > of a crow and couldn't quickly find one. If I ever get a chance, maybe I'll
> > see if I can take one myself on a cool day.
> >
> > -
>
> Sony cameras (at least last century) used a detector that was sensitive to the near IR.  Some took advantage of this having a mode in which the IR block filter was removed and an IR lamp was turned on.  I have a Sony video with this feature. In order to use it in daylight I put it in night mode and then used an IR pass filter.  It works well, for example when the fire in fireplace died out it still detected that it was still warm.
>
> bc  ….    found land scapes quite weird using this procedure.
>
> Note:  a very inexpensive IR pass only filter is one of Kodak’s developed colour films.  I’ve forgotten if it must be fully exposed first.  Various internet pages describe the procedure.
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--

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Dr. Keith S. Taber
https://science-education-research.com 
<https://science-education-research.com>

Emeritus Professor of Science Education
University of Cambridge
http://www.educ.cam.ac.uk/staff/taber.html

Senior Member
Homerton College, Cambridge

Editor-in-Chief, Royal Society of Chemistry Book Series:
/RSC Advances in Chemistry Education/ 
<https://science-education-research.com/advances-in-chemistry-education/>