nightshot?

"JamesDorset" wrote in message
newsan.2006.12.27.18.41.47.450372@firstcoastinte rnet.org...
Sony has a "nightshot" feature on some of their cameras and
video-cameras.
They advertise zero lux capability.

Besides turning on one or more infrared LEDs, do these cameras put an
infrared filter in front of the lens? Since the range of the IR LEDs
is
very limited, would "nightshot" give you an edge on recording aircraft
and
visible satellites at night?

For shooting aircraft and visible satellites at night, could a Canon
videocam simulate nightshot mode by putting an infrared lens in front
of
the lens? What would be the best video camera/lens combo for this type
of
filming?

I really appreciate any info.....


Be careful pointing anything that is an IR source at an aircraft -
especially things like police helicopters where their IR cameras
will see yours. They may perceive you as a threat of some sort
since your IR source will be obvious on their cameras. Personally,
I would rather not have them considering me a possible threat !!

mikey

"JamesDorset" wrote in message
newsan.2006.12.28.17.33.09.858502@firstcoastinte rnet.org...
On Wed, 27 Dec 2006 16:15:58 -0800, Mike Fields wrote:



Be careful pointing anything that is an IR source at an aircraft -
especially things like police helicopters where their IR cameras will
see yours. They may perceive you as a threat of some sort since your
IR
source will be obvious on their cameras. Personally, I would rather
not
have them considering me a possible threat !!

mikey

I agree wholeheartedly.

But there's no real worry about the IR LED in one of these nightshots.
The power is so very low that I doubt any of them has a range greater
than
20 feet. If a helicopter is that low, I submit you've got bigger
problems
(a la Vic Morrow)!

Not exactly what I meant. True, there is no danger from the IR LED
in the camera, HOWEVER, if the police perceive that someone may
be targeting them, (since the IR will show up like a bright light
if pointed at them on their night-vision) that is the problem (and
there have been enough cases of that to justify their fears).

mikey

Mike Fields wrote:

"JamesDorset" wrote in message
newsan.2006.12.28.17.33.09.858502@firstcoastinte rnet.org...

On Wed, 27 Dec 2006 16:15:58 -0800, Mike Fields wrote:



Be careful pointing anything that is an IR source at an aircraft -
especially things like police helicopters where their IR cameras will
see yours. They may perceive you as a threat of some sort since your IR
source will be obvious on their cameras. Personally, I would rather not
have them considering me a possible threat !!

mikey


I agree wholeheartedly.

But there's no real worry about the IR LED in one of these nightshots.
The power is so very low that I doubt any of them has a range greater
than
20 feet. If a helicopter is that low, I submit you've got bigger
problems
(a la Vic Morrow)!


Not exactly what I meant. True, there is no danger from the IR LED
in the camera, HOWEVER, if the police perceive that someone may
be targeting them, (since the IR will show up like a bright light
if pointed at them on their night-vision) that is the problem (and
there have been enough cases of that to justify their fears).

mikey

A standard incandescent bulb, including a flashlight puts out
a lot of infrared light, in fact more infrared than visible.
So IR LEDs are small IR light sources in the scheme of things.

Roger

Mike Fields wrote:
Be careful pointing anything that is an IR source at an aircraft -
especially things like police helicopters where their IR cameras
will see yours. They may perceive you as a threat of some sort
since your IR source will be obvious on their cameras. Personally,
I would rather not have them considering me a possible threat !!

The IR camera on police helicopters are mostly thermal, the IR an LED
puts out is much shorter in wavelength.

Scott

Scott W wrote:

Mike Fields wrote:
Be careful pointing anything that is an IR source at an aircraft -

especially things like police helicopters where their IR cameras
will see yours. They may perceive you as a threat of some sort
since your IR source will be obvious on their cameras. Personally,
I would rather not have them considering me a possible threat !!

The IR camera on police helicopters are mostly thermal, the IR an LED
puts out is much shorter in wavelength.

Scott

That's a good point. Thermal infrared cameras will work
predominantly in the 8 to 12 micron range. Visible light
is about .4 to .7 micron. IR LEDs put out light near
1 micron. Incandescent bulbs peak output between 1 and 2
microns. (By the way, for those interested, the reason
why fluorescent lights are so efficient is that most
of their energy goes into the visible band, whereas with
incandescent bulbs put out most of their energy in the
near-infrared.) (We need some infrared he another snow
storm is starting to bury Denver again.)

Roger