For consumer-level gear, that tech went out quite a while ago in
technology terms. Single-sensor chips that do color have been the norm
for years. To the best of my knowing, the only current cameras using the
three-sensor method are *WAY* out of reach of "Joe Consumer". Their main
users are folks like Lucas and Spielberg - People who have the budget to
spend amounts that have 5 or more figures to the left of the decimal
point on a camera. If the Jaycar unit he's got is similar to the
"XCam-2" units I've got (I'd expect they're so close to identical that
the differences don't matter) then it's DEFINITELY a single-sensor unit.
Not likely - Most (if not all) consumer-grade sensors are more sensitve
to IR than anything else, and the IR sensitivity, combined with IR
focussing slightly differently than visible light, results in a "fogged"
image, so some camera makers drop in an IR-cut filter between aperture
and sensor. But that isn't quite the same thing as the sensor being
blind to IR.
If his camera is the type with an IR filter, that's probably true - It's
*DESIGNED* to not shoot IR worth diddly. If it's one of the unusual ones
that doesn't, he's got a garbage illuminator and a perfectly legit gripe.
Jason -
You may very well need to take your camera apart and remove the IR
filter - Often a clear disk or sheet mounted somewhere between the
aperture and the sensor, which will be easy to remove, but could be a
coating on either the lens or the sensor itself, in which case, unless
you can figure out a solvent that will take it off without destroying
the underlying surface (lots of luck with that...) there's not much you
can do but put the camera back together and live with it as-is.
18 LEDs isn't that potent of an illuminator - The ones I've seen that do
a good job have 50 or more, and the top-of-the-line LED-based IR
illuminators often have more than 200 LEDs.
Try this: Point the illuminator directly at the camera from a couple
feet away. If the image "flares out" (like what happens if you point it
at the sun, a spotlight, or similar high-intensity light source), then
it probably isn't the camera, but the illuminator. If it doesn't
"flare", then either the illuminator isn't working, or the camera has an
IR-cut filter in it. If you can see a dim red glow from the illuminator,
then it's definitely working, and if the image doesn't flare when you
point it at the camera, the camera is almost certainly fitted with an
IR-cut filter.
If you find that it "flares", you might have luck with "dialing down" an
incandescent lamp, like a (*NOT* LED) Mag-Light or one of those "million
candlepower" spotlights - Put a good beefy pot inline with the power
source and adjust it so that the filament is "choked down" to a faint
red glow. At that point, most of the output is IR, and it should do a
relatively decent job.
Another method I tried that seemed to work fairly well was taking one of
those "black" CD-Rs (The plastic is black under visible light, but to
IR, it's as transparent as window glass is to visible light - it *HAS*
to be in order for the IR laser in the CD drive to be able to read the
data from it) polishing the "label" side down to the black plastic (to
remove the label, reflective and dye layers) and then fitting it to a
Coleman "Million Candlepower" spotlight in front of the original glass
lens. Leaving the center hole open will give you a handy way of knowing
exactly where the beam is hitting, or you can tape a nickel over the
hole if you're trying to do "I can see you, but you can't see me" type
work from a fixed position.
Caveat: Don't expect crisply focused images when shooting in IR - Due to
the wavelength difference, IR and visible light focus in different
places. A lens/pinhole focus system built for visible light is going to
put the focus point either ahead of or behind (Without looking it up, I
forget which way the focus point moves, but it does indeed move) the
plane of the sensor when used for IR, leaving the image at least
slightly blurred if you've set the focus using a visible light image.
--
Don Bruder -
[email protected] - If your "From:" address isn't on my
whitelist,
or the subject of the message doesn't contain the exact text
"PopperAndShadow"
somewhere, any message sent to this address will go in the garbage without
my
ever knowing it arrived. Sorry... <
http://www.sonic.net/~dakidd> for more
info