Economy thermal imager?

Possibly related to your comment on colour degrading, or perhaps not, is
the IR lased diodes. When I have seen them (5mw single mode types,
looked at directly at range greater than 1 foot, almost certainly
eye-safe conditions) they go beyond the wine or rubt reds of visible
types. The impression is of a maroon colour. (Yep, maroon, I ought to
have mentioned it earlier in this thread, no? > And what makes THAT
interesting is that it implies a bluish interpretation! Interesting
given that deep violet at the other end hints at a reddish
interpretation of what is just a very deep blue. Life is full of
cylic/linear transforms, but this is the single weirdest one I know.

This reminds me of sensing some barely visible IR LEDs as emitting a
slightly orangish shade of red. I have seen their spectra with a
diffraction grating, and I know that I am seeing only very long
wavelengths past 750 nm, generally past 800 nm. I have seen the
slightly orangish shade of red in the long wavelength spectral region
shown by the diffraction grating, with the shorter wavelength end of the
spectral band appearing to me closer to pure red in color.

I have heard of this being called "color reversal" or "infrared color
reversal".

As for the soldering iron tip becoming more focused but still
appearing
gray when viewed with central vision: I suspect that there are some
rods in central vision, in smaller and more closely spaced clusters to
achieve better resolution. Possibly photopic vision plays enough of a
role to increase sensation of resolution, however. However, I do see
dimly gray-appearing incandescent objects becoming invisible when viewed
entirely with the most central degree or two of vision. And when I look
at such an object that partially falls into the supposedly rod-free
most-central degree or two of vision, I sometimes tend to see the whole
thing anyway - maybe I get prone to "seeing things" under such
conditions.

don_at_manx.misty.com (Don Klipstein) wrote in
news:slrnh7u4fu.rnt.don_at_manx.misty.com:

Possibly related to your comment on colour degrading, or perhaps not, is
the IR lased diodes. When I have seen them (5mw single mode types,
looked at directly at range greater than 1 foot, almost certainly
eye-safe conditions) they go beyond the wine or rubt reds of visible
types. The impression is of a maroon colour. (Yep, maroon, I ought to
have mentioned it earlier in this thread, no? > And what makes THAT
interesting is that it implies a bluish interpretation! Interesting
given that deep violet at the other end hints at a reddish
interpretation of what is just a very deep blue. Life is full of
cylic/linear transforms, but this is the single weirdest one I know.

This reminds me of sensing some barely visible IR LEDs as emitting a
slightly orangish shade of red. I have seen their spectra with a
diffraction grating, and I know that I am seeing only very long
wavelengths past 750 nm, generally past 800 nm. I have seen the
slightly orangish shade of red in the long wavelength spectral region
shown by the diffraction grating, with the shorter wavelength end of the
spectral band appearing to me closer to pure red in color.

I have heard of this being called "color reversal" or "infrared color
reversal".


Weird. I have read of this before, but I don't know why it should be. The
maroon I sort of understand, it fits with a kind of mapping of spectrum as
circle, a standard practise in Microsoft colour picker dialogs for example..
Maybe our brains give interpretations to fit models we already have? These
models may work at a very primal level too.

As for the soldering iron tip becoming more focused but still
appearing
gray when viewed with central vision: I suspect that there are some
rods in central vision, in smaller and more closely spaced clusters to
achieve better resolution. Possibly photopic vision plays enough of a
role to increase sensation of resolution, however. However, I do see
dimly gray-appearing incandescent objects becoming invisible when viewed
entirely with the most central degree or two of vision. And when I look
at such an object that partially falls into the supposedly rod-free
most-central degree or two of vision, I sometimes tend to see the whole
thing anyway - maybe I get prone to "seeing things" under such
conditions.


Brains again.. I've noticed mine has an amazing ability to fill in missing
detail. Can be the cause of error as much as a cure for it. It's entirely
possible that although I do see that weakly hot iron in the centre of my
vision, any impression of better definition is purely my brain filling in
because it expects it, and knows what the iron looks like already. The
silhouette of the guard coil was real though, it presented itself as an
unfamiliar effect somehow even though logically I should have expected to see
it. I've learned to gauge when my brain is 'filling in' because when that
happens the impression often has a suspiciously familiar aspect when a true
new observation probably could not feel that way. But I usually avoid this
when trying to establish a fact, it's the equivalent of trying to design for
an op-amp at an extreme of its capability.

One thing I do remember, looking at a comet. That vanished when I looked
directly at it. The only way to see it was with peripheral vision, and to
keep moving slowly, too, so it triggered new cells and didn't get lost in
noise and distractions. Different spectrum of light, but still obviously
scotopic..

"JosephKK"<quiettechblue_at_yahoo.com> wrote in
news:jk4o751192hv04vit912ulhssfp7048dsl_at_4ax.com:

IIRC many common soldering irons run in the 600 F to 700 F range (not
all that far from visible glow) and may well output enough for a
modified digicam. I swear, that as child i could see the soldering
iron by its own glow (in the middle of the night when i woke for some
reason) some night when i left it plugged in.


I believe it. I've seen them at times. I can't tell when sight ends and
imagination begins though, I tried.. > I have a nice temperature controlled
iron now so I'll try this again some time. Helps to try to see it with the
rods, not the cones, so at least thirty degrees to the side.

Simply put, just harmonics (frequency doubling/tripling). Many more
complex things are significant contributors as well.

On Tue, 11 Aug 2009 14:10:54 -0500, Lostgallifreyan
no-one_at_nowhere.net> wrote:

don_at_manx.misty.com (Don Klipstein) wrote in
news:slrnh7u4fu.rnt.don_at_manx.misty.com:

Possibly related to your comment on colour degrading, or perhaps not, is
the IR lased diodes. When I have seen them (5mw single mode types,
looked at directly at range greater than 1 foot, almost certainly
eye-safe conditions) they go beyond the wine or rubt reds of visible
types. The impression is of a maroon colour. (Yep, maroon, I ought to
have mentioned it earlier in this thread, no? > And what makes THAT
interesting is that it implies a bluish interpretation! Interesting
given that deep violet at the other end hints at a reddish
interpretation of what is just a very deep blue. Life is full of
cylic/linear transforms, but this is the single weirdest one I know.
This reminds me of sensing some barely visible IR LEDs as emitting a
slightly orangish shade of red. I have seen their spectra with a
diffraction grating, and I know that I am seeing only very long
wavelengths past 750 nm, generally past 800 nm. I have seen the
slightly orangish shade of red in the long wavelength spectral region
shown by the diffraction grating, with the shorter wavelength end of the
spectral band appearing to me closer to pure red in color.

I have heard of this being called "color reversal" or "infrared color
reversal".

Weird. I have read of this before, but I don't know why it should be. The
maroon I sort of understand, it fits with a kind of mapping of spectrum as
circle, a standard practise in Microsoft colour picker dialogs for example..
Maybe our brains give interpretations to fit models we already have? These
models may work at a very primal level too.

Simply put, just harmonics (frequency doubling/tripling). Many more
complex things are significant contributors as well.

Might as well buy the real IR imagers that the security camera folks
are pushing now, if you are going to do that.

I think they sell them by the box at Frys'.

Also at the low sensitivity
needed for near IR most of the colour vision is gone for me so it is
essentially grey with a hint of orange.

brain as yellow-green. The eye cones are sensitive to yellow, green and
blue. Red is a construction of the brain.

You can have fun with this perceptual feature by using a neodymium
filter over the eyes which creates out of gamut colours for the brain to
contend with that are "redder than red" and "greener than green".

That relates to what Don Klipstein said, and I've been thinking about that..
it's ame for me if the source is low intensity, broadband, and at edges of
IR. Orangish greyish brownish.. But what if the source is narrowband, much
deeper into IR, and fairly strong? To me such sources (unlensed 5 mW laser
diodes, etc) look maroon, a distinct red that is so deep and dark it is to
red as deep violet is to blue. And both ends of the spectrum seem to reach
toward each other like the closing of a circle. Anyone else see it this way?

At the same time, Fischer Price sold a B&W "toy" camera for $150 that
could have a Ge or Pyrex lens or filter put on it, and it would do IR
very nicely.

Martin Brown <|||newspam|||@nezumi.demon.co.uk> wrote in
news:Fruhm.267740$Ta5.241754_at_newsfe15.iad:

Also at the low sensitivity
needed for near IR most of the colour vision is gone for me so it is
essentially grey with a hint of orange.

That relates to what Don Klipstein said, and I've been thinking about that..
it's ame for me if the source is low intensity, broadband, and at edges of
IR. Orangish greyish brownish.. But what if the source is narrowband, much
deeper into IR, and fairly strong? To me such sources (unlensed 5 mW laser
diodes, etc) look maroon, a distinct red that is so deep and dark it is to
red as deep violet is to blue. And both ends of the spectrum seem to reach
toward each other like the closing of a circle. Anyone else see it this way?

NB red is constructed by the
brain as yellow-green. The eye cones are sensitive to yellow, green and
blue. Red is a construction of the brain.

You can have fun with this perceptual feature by using a neodymium
filter over the eyes which creates out of gamut colours for the brain to
contend with that are "redder than red" and "greener than green".


Where can I get one? This needs trying. What form is the neodymium in,
obviously not metal sheet... Doped glass?

That relates to what Don Klipstein said, and I've been thinking about that..
it's ame for me if the source is low intensity, broadband, and at edges of
IR. Orangish greyish brownish.. But what if the source is narrowband, much
deeper into IR, and fairly strong? To me such sources (unlensed 5 mW laser
diodes, etc) look maroon, a distinct red that is so deep and dark it is to
red as deep violet is to blue. And both ends of the spectrum seem to reach
toward each other like the closing of a circle. Anyone else see it this way?

Years ago, I collected a set of LEDs with various wavelengths.
One was 700 nm. It was a very pleasant (to my eye) deep red.

On Wed, 22 Jul 2009 16:00:31 -0700, Archimedes' Lever wrote
(in article <9e6f65lgevbktpfqearr1g0dl3jm1jg...@4ax.com>):

  Might as well buy the real IR imagers that the security camera folks
are pushing now, if you are going to do that.

  I think they sell them by the box at Frys'.

When i search Frys.com for "infrared" I get all kinds of IR communication
devices (headphones, etc.), an intrusion-sensor security system, and one
security camera that uses IR illumination.

Is this what you mean? ::

http://www.frys.com/product/5382748?site=sr:SEARCH:MAIN_RSLT_PG

Thanks.

At the same time, Fisher Price sold a B&W "toy" camera for $150 that
could have a Ge or Pyrex lens or filter put on it, and it would do IR
very nicely.

At the same time, Fisher Price sold a B&W "toy" camera for $150 that
could have a Ge or Pyrex lens or filter put on it, and it would do IR
very nicely.

Where would one find such a lens to replace the standard lens?

Thanks.

On Fri, 24 Jul 2009 20:00:33 -0700, Archimedes' Lever
OneBigLever_at_InfiniteSeries.Org> wrote:

At the same time, Fischer Price sold a B&W "toy" camera for $150 that
could have a Ge or Pyrex lens or filter put on it, and it would do IR
very nicely.


Perfect proof that most in the group are idiots.

Not one comment on this well known anomaly as the years ticked by.