IR "floodlight" using LEDs?

[Joe]

<nospam.clare.nce@snyder.on.ca> wrote in message
news:87che0lp8h77j6vihdpj7c5b78u1r2k1id@4ax.com...

On Mon, 05 Jul 2004 00:23:44 -0000, buck rojerz
inorbit@outerspace.org> wrote:


I actually have one of those "dryer" lamps as you refer to them, except
mine is in a hand-held mineral light. It has a filter in front of it to
block out most of the visible light. By todays standards it isn't a very
bright black light. I have some B.L. leds that are much brighter than
the mineral light is. The mineral light has a small ballast on a line
cord going to the hand-held part, that encases the bulb. It still works
just fine. When you take the filter off, you quickly notice that the
bulb is also an ozone producer, as well. But I don't stare at it that
way... bad news, for sure. It looks just like the un-coated flourecsent
tubes. (I know, I said I didn't look at it.)

cheers

buck
A bit like the sign on the laser cutter "do not look into laser with
your remaining good eye"

What about photo flood lights?. They have a bluish coating over the bulb,
usually 125W minimum and a lifespan of 3 or 4 hrs?

Joe

 

[buck rojerz]

nospam.clare.nce@snyder.on.ca wrote in
news:87che0lp8h77j6vihdpj7c5b78u1r2k1id@4ax.com:

On Mon, 05 Jul 2004 00:23:44 -0000, buck rojerz
inorbit@outerspace.org> wrote:


I actually have one of those "dryer" lamps as you refer to them,
except mine is in a hand-held mineral light. It has a filter in front
of it to block out most of the visible light. By todays standards it
isn't a very bright black light. I have some B.L. leds that are much
brighter than the mineral light is. The mineral light has a small
ballast on a line cord going to the hand-held part, that encases the
bulb. It still works just fine. When you take the filter off, you
quickly notice that the bulb is also an ozone producer, as well. But
I don't stare at it that way... bad news, for sure. It looks just
like the un-coated flourecsent tubes. (I know, I said I didn't look
at it.)

cheers

buck
A bit like the sign on the laser cutter "do not look into laser with
your remaining good eye"

listen... I don't wear this eyepatch for nuthin... (grin)

buck

 

[Don Klipstein]

In article <QN2Gc.8500$yy1.5716@newsread2.news.atl.earthlink.net>, Joe wrote:

nospam.clare.nce@snyder.on.ca> wrote in message
news:87che0lp8h77j6vihdpj7c5b78u1r2k1id@4ax.com...
On Mon, 05 Jul 2004 00:23:44 -0000, buck rojerz
inorbit@outerspace.org> wrote:


I actually have one of those "dryer" lamps as you refer to them, except
mine is in a hand-held mineral light. It has a filter in front of it to
block out most of the visible light. By todays standards it isn't a very
bright black light. I have some B.L. leds that are much brighter than
the mineral light is. The mineral light has a small ballast on a line
cord going to the hand-held part, that encases the bulb. It still works
just fine. When you take the filter off, you quickly notice that the
bulb is also an ozone producer, as well. But I don't stare at it that
way... bad news, for sure. It looks just like the un-coated flourecsent
tubes. (I know, I said I didn't look at it.)

cheers

buck
A bit like the sign on the laser cutter "do not look into laser with
your remaining good eye"

What about photo flood lights?. They have a bluish coating over the bulb,
usually 125W minimum and a lifespan of 3 or 4 hrs?

They are the same as the uncolored ones. These are rather ordinary
incandescents with the filament operated at a higher temperature than
usual. The blue coloring removes some of the red and yellow light ans a
small amount of the green light to make the color more like that of
sunlight. Without the blue coloring, the nominal color temperature is
3400 Kelvin. The uncolored ones produce about 1.65-1.75 times as much
light as an incandescent of the same voltage and wattage and a more usual
life expectancy of 750 hours.
Higher wattage 3400K lamps have longer but still short life expectancy -
6 hours for the 500 watt and 10 hours for the 1000 watt.

I would advise against staring into these, but I don't expect instant
eye damage from very briefly looking directly at one - at least any of
the frosted ones, and my experience so far is that these are normally
frosted. In any case, tungsten at 3400 Kelvin is not as bad to look at as
the Sun is...

Then there are the short life halogen movie and video lamps and
projection lamps... Those usually have color temp. around 3300-3400 K and
are usually clear rather than frosted. I have looked at these enough
times (never for long) and I don't think I have any eye damage from these
yet, but I would advise against staring into them or looking directly at
filaments that hot for more than a fraction of a second. I have a rough
calculation that a couple seconds of staring at these is safe (assuming
one's pupils constrict), but then staring into a 1 milliwatt laser for 1
second is supposedly safe (barely) - something I would advise against
doing.

- Don Klipstein (don@misty.com)

 

[David Wood]

More FYI. The commercially available IR illuminators I've seen cost in
the area of $1 for every IRED they contain. I can build them for about
half that using an LM317 in the current regulating mode and surplus
880 nM IREDs. The longest range I've seen advertised for one was 140
feet (what does that range mean given the various sensitivities of the
cameras). It was about the size of a mailbox and included a
collimating lens.

 

[DougC]

Don Bruder wrote:

OK, guys... you've all been having so much fun with LED flashlights, now
here's one for ya:

Show me some plans for a floodlight/spotlight (ideally, adjustable
between the two) *USING IR LEDs* that will light up a goodly section of
territory - Enough to make decent moonless-night video of deer with a
camera that has demonstrated itself to be QUITE nicely sensitive to the
IR wavelength used by all the remote controls I've got in the house.

It won't work. I have tried. The unfocused/unreflected LED's will only
illuminate out to about 15-20 feet, if you are using a gen-1 NV tube
viewer, and a CCD-camera is about equal to that at best. You can put one
IR LED into a flashlight-base and put it in a flashlight (with a
dropping resistor) and get a -fairly- good small beam out to 40-50 feet
or so, but the flashlight you use MUST have a sweep focus, that can
adjust from spotlight to flood. Because the "flood" setting doesn't
illuminate very far, but the "spot" setting is too bright to be of much
use up close. ....THere are companies that sell IR-LED heads that they
say are for this. I have not tried any of them, but from my own attempts
(with a 19-LED unreflected unit, as well as a couple single-LED
reflected attempts) in a Mag-light body I would say it doesn't work.
-----
The best way to make a IR light source for a gen-1 or CCD camera is also
the easiest way: use a regular flashlight, regular bulb and get a
deep-IR glass photographic filter. These filters will not allow any
visible light through at all, but they are expensive: the Hoya-RM90 is
one. A much cheaper way is to put a deep-red and deep-blue filter over a
regular flashlight. This is visible-red if you are looking right into
it, but the light it casts is not visible--yet shows brightly in gen-1
NV scopes. CCD cameras catch it well too, if they have no IR filter. As
to how well the animals can see this, I don't know. My experience was
that wildlife were far more concerned about noises than a red light, but
you may be after different animals.
-----
If you really want to see in the dark [WITHOUT using active lighting]
the -only- way is to get a gen-2 or gen-3 night-vision scope, one that
adapts onto your camera of course. Figure $1200+ US for a gen-2, $1800+
US for a gen-3. This will allow you to film in any lighting
circumstances outdoors, probably without any additional lighting at all.
-----
As a sidenote, I also have tried stacking two gen-1 scopes. By taking
the eyepiece off one, and holding that up right in front of the other.
It doesn't really accomplish much; the image is somewhat brighter but
far less clear--the "background noise" brightens more than the image.
You need to use an f-stop on the scopes to see anything at all--I used
pieces of kraft paper over both lenses, with small holes cut centered in
them about 10mm across--or else the rearmost image turns up too bright.
Two cascaded $100 gen-1's won't equal a single $1000 gen-2. Gen-1 NV
tubes use electron inverters internally, that drastically ruin/blur the
images they produce. A gen-2 or gen-3 NV scope image is far more clear
than a gen-1 is, and amplifies light higher and with less noise as well.
~~~~~~~~

 

[Watson A.Name - \"Watt Su]

"DougC" <nobody@charter.net> wrote in message
news:10g2dgct0oso972@corp.supernews.com...

Don Bruder wrote:
OK, guys... you've all been having so much fun with LED flashlights,
now
here's one for ya:

Show me some plans for a floodlight/spotlight (ideally, adjustable
between the two) *USING IR LEDs* that will light up a goodly section
of
territory - Enough to make decent moonless-night video of deer with
a
camera that has demonstrated itself to be QUITE nicely sensitive to
the
IR wavelength used by all the remote controls I've got in the house.

Thanks for all the good info below. I think I would get one of those
300 to 500 Watt construction lights, and put a bunch of gells in front
of it. I've read that they can be obtained from theater supply stores.

It won't work. I have tried. The unfocused/unreflected LED's will only
illuminate out to about 15-20 feet, if you are using a gen-1 NV tube
viewer, and a CCD-camera is about equal to that at best. You can put
one
IR LED into a flashlight-base and put it in a flashlight (with a
dropping resistor) and get a -fairly- good small beam out to 40-50
feet
or so, but the flashlight you use MUST have a sweep focus, that can
adjust from spotlight to flood. Because the "flood" setting doesn't
illuminate very far, but the "spot" setting is too bright to be of
much
use up close. ....THere are companies that sell IR-LED heads that they
say are for this. I have not tried any of them, but from my own
attempts
(with a 19-LED unreflected unit, as well as a couple single-LED
reflected attempts) in a Mag-light body I would say it doesn't work.
-----
The best way to make a IR light source for a gen-1 or CCD camera is
also
the easiest way: use a regular flashlight, regular bulb and get a
deep-IR glass photographic filter. These filters will not allow any
visible light through at all, but they are expensive: the Hoya-RM90 is
one. A much cheaper way is to put a deep-red and deep-blue filter over
a
regular flashlight. This is visible-red if you are looking right into
it, but the light it casts is not visible--yet shows brightly in gen-1
NV scopes. CCD cameras catch it well too, if they have no IR filter.
As
to how well the animals can see this, I don't know. My experience was
that wildlife were far more concerned about noises than a red light,
but
you may be after different animals.
-----
If you really want to see in the dark [WITHOUT using active lighting]
the -only- way is to get a gen-2 or gen-3 night-vision scope, one that
adapts onto your camera of course. Figure $1200+ US for a gen-2,
$1800+
US for a gen-3. This will allow you to film in any lighting
circumstances outdoors, probably without any additional lighting at
all.
-----
As a sidenote, I also have tried stacking two gen-1 scopes. By taking
the eyepiece off one, and holding that up right in front of the other.
It doesn't really accomplish much; the image is somewhat brighter but
far less clear--the "background noise" brightens more than the image.
You need to use an f-stop on the scopes to see anything at all--I used
pieces of kraft paper over both lenses, with small holes cut centered
in
them about 10mm across--or else the rearmost image turns up too
bright.
Two cascaded $100 gen-1's won't equal a single $1000 gen-2. Gen-1 NV
tubes use electron inverters internally, that drastically ruin/blur
the
images they produce. A gen-2 or gen-3 NV scope image is far more clear
than a gen-1 is, and amplifies light higher and with less noise as
well.
~~~~~~~~

 

[Dr Engelbert Buxbaum]

Watson A.Name - \Watt Sun, the Dark Remover\ wrote:

Thanks for all the good info below. I think I would get one of those
300 to 500 Watt construction lights, and put a bunch of gells in front
of it. I've read that they can be obtained from theater supply stores.

Just watch for the heat produced by such a beast.

 

[Rich Grise]

Dr Engelbert Buxbaum wrote:

Watson A.Name - \Watt Sun, the Dark Remover\ wrote:

Thanks for all the good info below. I think I would get one of those
300 to 500 Watt construction lights, and put a bunch of gells in front
of it. I've read that they can be obtained from theater supply stores.

Just watch for the heat produced by such a beast.

Well, isn't that kinda the point? They are looking for IR, after all.

Cheers!
Rich