Don Bruder
June 29th 04, 03:58 AM
Hi folks...
An evil plot has come upon me, and I'm seeking some help in the "how
to?" and "how much?" departments.
First, let me assure you that this *IS NOT* aimed at the idea of
firearms use at night, although I'm aware that it could be put to such
an application if one desired to do so. The only shooting I plan on
doing with this rig (Assuming I can assemble it to begin with!) uses
videotape and/or photographic film as ammunition. Having said that...
I want to watch the deer. Without disturbing them or the neighbors. I
know we have a very large population of them around here, and that they
come and go like crazy at night (the tracks are impossible to miss,
they're even right up alongside buildings and vehicles, and one morning,
I went out to feed the horses, and there were deer prints from the wet
grass onto the concrete garage floor!) but come daylight, other than the
tracks and occasional droppings, they might as well not exist. Here's
where the "evil plot" part comes in...
I've got the cameras and related materials to tape/shoot in infrared. It
actually works decently using the IR from TV remotes as the "spotlight",
but due to the relatively low level, that's no good at anything beyond a
few feet.
That got me thinking about building an IR floodlight to go with the
cameras. My first thought, being mainly an electronics geek, was "A
whole bunch of IR LEDs, just like the ones in the TV remotes". Problem:
Power dissipation. Them puppies are gonna be making some heat. Problem
2: expensive.
OK, that idea MIGHT work, but a better one is in order. I've got one of
those "2 million candlepower" spotlights. Now there's a light source...
Except it's visible light, and I already know the deer are skittish
about headlights, flashlights, and similar. (I come upon them often when
coming home from work late at night - they usually make tracks for
"anywhere but here!" as quick as they can once the headlights hit 'em)
On the other hand, they're "tuned" for UV sensitivity - The other end of
the spectrum, as I probably don't need to specify - and everything I can
find says that they're either blind, or very close to it, to infrared.
So, if I take a filter that blocks visible light, slap it up in front of
my spotlight, and point it at a deer, the deer might notice a slight
warmth, but otherwise be unaware of the light. Meanwhile, my video
camera is showing me and/or recording realtime footage that's either the
whole point of that session, or tells me I've got the light pointed in
the right place, and at the same time aims the still camera. Meanwhile,
the still camera, mounted above the video camera so that they're both
pointing at the same place, is being lined up to snap the IR picture
that the video is seeing.
OK, OK, OK, I know... I'm rambling on. My apologies.
Now that I've figured this much out for myself, I need some expertise
from the photography buffs out there. I've found what I think SHOULD be
the filter I need. The problem is that "should be" and "it is" is a
distinction I don't have the knowledge to make, but you might.
One online source for it is <http://www.adorama.com/KKWFG87.html>
It's billed as being a "Kodak Wratten Gelatin Filter 75mm/3x3" Opaque
#87 Infrared". The description sounds promising, at least, as far as it
goes - "Visibly opaque filters absorb unwanted visible light in infrared
photography."
Based on the info I've supplied so far, would this item be likely to
accomplish the task I'm getting ready to put it to? If not, what would
be your suggestion as far as filters that I might use? I can't help but
notice it's rather pricey, at 55 dollars for a 3 inch square (No, I
don't have the measurements of my light handy, but I'll be checking on
that next) and I'd rather not be needing to replace it very often. It
sounds like it might be rather fragile, based on the fact that it's
called a "gelatin" filter. Will it survive for very long? And if it is
fragile, any suggestions for extending its working life?
Thanks for wading through this long-winded brain-pick!
--
Don Bruder - - New Email policy in effect as of Feb. 21, 2004.
I respond to Email as quick as humanly possible. If you Email me and get no
response, see <http://www.sonic.net/~dakidd/main/contact.html> Short
form: I'm trashing EVERYTHING that doesn't contain a password in the subject.
An evil plot has come upon me, and I'm seeking some help in the "how
to?" and "how much?" departments.
First, let me assure you that this *IS NOT* aimed at the idea of
firearms use at night, although I'm aware that it could be put to such
an application if one desired to do so. The only shooting I plan on
doing with this rig (Assuming I can assemble it to begin with!) uses
videotape and/or photographic film as ammunition. Having said that...
I want to watch the deer. Without disturbing them or the neighbors. I
know we have a very large population of them around here, and that they
come and go like crazy at night (the tracks are impossible to miss,
they're even right up alongside buildings and vehicles, and one morning,
I went out to feed the horses, and there were deer prints from the wet
grass onto the concrete garage floor!) but come daylight, other than the
tracks and occasional droppings, they might as well not exist. Here's
where the "evil plot" part comes in...
I've got the cameras and related materials to tape/shoot in infrared. It
actually works decently using the IR from TV remotes as the "spotlight",
but due to the relatively low level, that's no good at anything beyond a
few feet.
That got me thinking about building an IR floodlight to go with the
cameras. My first thought, being mainly an electronics geek, was "A
whole bunch of IR LEDs, just like the ones in the TV remotes". Problem:
Power dissipation. Them puppies are gonna be making some heat. Problem
2: expensive.
OK, that idea MIGHT work, but a better one is in order. I've got one of
those "2 million candlepower" spotlights. Now there's a light source...
Except it's visible light, and I already know the deer are skittish
about headlights, flashlights, and similar. (I come upon them often when
coming home from work late at night - they usually make tracks for
"anywhere but here!" as quick as they can once the headlights hit 'em)
On the other hand, they're "tuned" for UV sensitivity - The other end of
the spectrum, as I probably don't need to specify - and everything I can
find says that they're either blind, or very close to it, to infrared.
So, if I take a filter that blocks visible light, slap it up in front of
my spotlight, and point it at a deer, the deer might notice a slight
warmth, but otherwise be unaware of the light. Meanwhile, my video
camera is showing me and/or recording realtime footage that's either the
whole point of that session, or tells me I've got the light pointed in
the right place, and at the same time aims the still camera. Meanwhile,
the still camera, mounted above the video camera so that they're both
pointing at the same place, is being lined up to snap the IR picture
that the video is seeing.
OK, OK, OK, I know... I'm rambling on. My apologies.
Now that I've figured this much out for myself, I need some expertise
from the photography buffs out there. I've found what I think SHOULD be
the filter I need. The problem is that "should be" and "it is" is a
distinction I don't have the knowledge to make, but you might.
One online source for it is <http://www.adorama.com/KKWFG87.html>
It's billed as being a "Kodak Wratten Gelatin Filter 75mm/3x3" Opaque
#87 Infrared". The description sounds promising, at least, as far as it
goes - "Visibly opaque filters absorb unwanted visible light in infrared
photography."
Based on the info I've supplied so far, would this item be likely to
accomplish the task I'm getting ready to put it to? If not, what would
be your suggestion as far as filters that I might use? I can't help but
notice it's rather pricey, at 55 dollars for a 3 inch square (No, I
don't have the measurements of my light handy, but I'll be checking on
that next) and I'd rather not be needing to replace it very often. It
sounds like it might be rather fragile, based on the fact that it's
called a "gelatin" filter. Will it survive for very long? And if it is
fragile, any suggestions for extending its working life?
Thanks for wading through this long-winded brain-pick!
--
Don Bruder - - New Email policy in effect as of Feb. 21, 2004.
I respond to Email as quick as humanly possible. If you Email me and get no
response, see <http://www.sonic.net/~dakidd/main/contact.html> Short
form: I'm trashing EVERYTHING that doesn't contain a password in the subject.