Please explain

In article ,
"T3" wrote:

One evening about 7 years ago (around twilight) as I was docking my
boat, a single F/A18 was dropping to attack altitude at what appeared
to be mil speed and as he came by(approx200ft on the left) I noticed
what appeared to be an iridescent green box just forward and under of
the canopy on the left side. As a 30 year aircraft mechanic for Pan
Am it has always bothered me that I had no valid explanation for it.

Look at this photo:

http://www.fas.org/man/dod-101/sys/ac/f-18-bnd980501219.jpg

See the three rectangles just under the number "731" on the nose?

Those are electroluminescent lights, used for formation flying at night.
They put out a mild greenish-yellow glow.

They're related to the EL backlights seen on watches.

--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.

Great picture Chad,
I'm thinkin that with NVS, the lights are blue? Not sure, but it would
make sense. I know before NVS came out the formation lights were all
green, but this would overdrive and blind NVG's. Wouldn't changing the
lights to blue be part of the NVS mod, or do they just keep em turned
off?

On Tue, 11 Nov 2003 17:53:26 GMT, Chad Irby wrote:

In article ,
"T3" wrote:

One evening about 7 years ago (around twilight) as I was docking my
boat, a single F/A18 was dropping to attack altitude at what appeared
to be mil speed and as he came by(approx200ft on the left) I noticed
what appeared to be an iridescent green box just forward and under of
the canopy on the left side. As a 30 year aircraft mechanic for Pan
Am it has always bothered me that I had no valid explanation for it.

Look at this photo:

http://www.fas.org/man/dod-101/sys/ac/f-18-bnd980501219.jpg

See the three rectangles just under the number "731" on the nose?

Those are electroluminescent lights, used for formation flying at night.
They put out a mild greenish-yellow glow.

They're related to the EL backlights seen on watches.

I'm thinkin that with NVS, the lights are blue? Not sure, but it would
make sense. I know before NVS came out the formation lights were all
green, but this would overdrive and blind NVG's.

Actually Green lighting is better than Blue lighting for NVGs. Anything with
shades of Red light (Green + Red = Blue) will wash out the NVGs.


BUFDRVR

"Stay on the bomb run boys, I'm gonna get those bomb doors open if it harelips
everyone on Bear Creek"

BUFDRVR wrote:
I'm thinkin that with NVS, the lights are blue? Not sure, but it
would make sense. I know before NVS came out the formation lights
were all green, but this would overdrive and blind NVG's.

Actually Green lighting is better than Blue lighting for NVGs.
Anything with shades of Red light (Green + Red = Blue) will wash out
the NVGs.

Green + Red = Blue???
Mind boggles.

--
James...
http://www.jameshart.co.uk/

Green + Red = Blue???
Mind boggles.

hmm, doesn't it? I have an idiglo Timex that has a blue light, I was told by
the NVG instructor in my squadron that it would work well enough, but would
have been better if it were green. He then gave me that exact line I gave you
above, anything with shades of red in it will tend to wash out NVGs. Anyone out
there have a clue better than mine? Any color spectrum experts?


BUFDRVR

"Stay on the bomb run boys, I'm gonna get those bomb doors open if it harelips
everyone on Bear Creek"

(BUFDRVR) wrote in message ...
Green + Red = Blue???
Mind boggles.

hmm, doesn't it? I have an idiglo Timex that has a blue light, I was told by
the NVG instructor in my squadron that it would work well enough, but would
have been better if it were green. He then gave me that exact line I gave you
above, anything with shades of red in it will tend to wash out NVGs. Anyone out
there have a clue better than mine? Any color spectrum experts?

I believe what he was referring to is the fact that red, green, and
blue are *the* primary colors. As blue is one of those primary colors,
it is not a product of the other two. Red plus green actually yields
yellow.

Brooks



BUFDRVR

"Stay on the bomb run boys, I'm gonna get those bomb doors open if it harelips
everyone on Bear Creek"

In article ,
(Kevin Brooks) wrote:



I believe what he was referring to is the fact that red, green, and
blue are *the* primary colors.
Er, isn't that red, green, and yellow?

BUFDRVR wrote:

Green + Red = Blue???
Mind boggles.


hmm, doesn't it? I have an idiglo Timex that has a blue light, I was told by
the NVG instructor in my squadron that it would work well enough, but would
have been better if it were green. He then gave me that exact line I gave you
above, anything with shades of red in it will tend to wash out NVGs. Anyone out
there have a clue better than mine? Any color spectrum experts?


BUFDRVR

"Stay on the bomb run boys, I'm gonna get those bomb doors open if it harelips
everyone on Bear Creek"


The green plus red is blue boggles my mind.

Still,

I wouldn't call myself a colour spectrum expert, but I'll give it a try:
The NVGs are most sensitive to light at the low frequency/ long
wavelength end of the visual spectrum, i.e. the red end of the spectrum
(and unlike the human eye even is sensitive to somewhat lower
frequencies in the IR range).
Green is associated with higher frequencies/smaller wavelengths than
red. A red light of a certain intensity produces a far stronger response
in the NVG than a green light of similar intensity would, since green
lies further away from the wavelength range to which the NVGs are most
susceptible. Pretty straightforward.
As for the blue, this is associated with even higher frequencies/smaller
wavelengths than the green, so it should be even less visible, which
gives no explanation whatsoever for why green would work better than
blue, unless with blue the worry would be that you wouldn't bee able to
see that at all, while wearing your NVGs.

Regards,
Ralph Savelsberg

The green plus red is blue boggles my mind.

Still,

I wouldn't call myself a colour spectrum expert, but I'll give it a try:
The NVGs are most sensitive to light at the low frequency/ long
wavelength end of the visual spectrum, i.e. the red end of the spectrum
(and unlike the human eye even is sensitive to somewhat lower
frequencies in the IR range).
Green is associated with higher frequencies/smaller wavelengths than
red. A red light of a certain intensity produces a far stronger response
in the NVG than a green light of similar intensity would, since green
lies further away from the wavelength range to which the NVGs are most
susceptible. Pretty straightforward.
As for the blue, this is associated with even higher frequencies/smaller
wavelengths than the green, so it should be even less visible, which
gives no explanation whatsoever for why green would work better than
blue, unless with blue the worry would be that you wouldn't bee able to
see that at all, while wearing your NVGs.

Wow, this thread has gotten good, imagine that I'm actually learning here.
Unfortunately, I obviously misunderstood the NVG experts words, I thought he
said blue light was closer to the red spectrum than green, but if you're
correct (as well as another poster who posted the exact frequencies for each
color...impressive), I must have misunderstood. Anyway, he was correct, my blue
indiglo watch washed out my NVG's, if only slightly, while the green light of
similar intensity did not.


BUFDRVR

"Stay on the bomb run boys, I'm gonna get those bomb doors open if it harelips
everyone on Bear Creek"

"BUFDRVR" wrote in message
...
Green + Red = Blue???
Mind boggles.

hmm, doesn't it?

Green is yellow + blue