What is the main difference
between Generation 2 and Generation 3 night vision ?
The primary difference between the two generations
is the photocathode. Generation 2 uses a multi alkali photocathode
while Generation 3 uses Gallium Arsenide. Gallium
Arsenide provides a significant increase in photoresponse
and tube life. Other differences in performance will be image
tube resolution, tube gain and signal to noise ratio. Therefore
Generation 3 offers greater clarity but is generally more expensive
than Generation 2. Generation 2 night vision works well in most
situations while Generation 3 will achieve high performance in
all conditions.
What is Generation 3?
Generation 3 is categorically the highest performance image intensifier tube technology available. ITT Image intensifier tubes are manufactured for the U.S. Department of Defense under “OMNIBUS” contracts. The current contract (effective 2007) is OMNIBUS VII. Generation 3 technology has been improved over the years. Older Gen 3 tubes do not perform to the same levels as those produced today.
Can Generation 1 be useful?
Yes, Generation 1 can be useful in most nighttime
situations. Newer Generation 1 devices do offer increased performance
from there older predecessors. Generation 1 units typically use
an S-20 photocathode and electrostatic inversion to achieve gain.
They can offer substantial resolution toward the center of the
image tube, while the edges may be blurred. Generation 1 devices
are usually inexpensive and can be a good start for the night
vision enthusiast.
What can I expect an image tube to look
like?
All image tubes, regardless of the generation,
will provide a green illuminated picture of the scene that you
are viewing. No night vision tube is exactly the same. Because
of the manufacturing processes, all night vision image tubes will
have different cosmetics such as small
spots or specs, photocathode coloring, or a chicken wire effect
from the microchannel plate. Most cosmetics are only noticed during
viewing in high light situations such as viewing with the daylight
filter on in a lit room. Most cosmetic blemishes are not noticeable
during normal nighttime operation but may still be seen to some
degree in certain situations. These cosmetics in no way effect
the performance of the image tube and do not decrease the ability
to perform nighttime tasks. Resolution and gain will also affect
the appearance of any night vision system. Most commercial and
military systems have been thoroughly tested to ensure reliability
once in use.
Why is night vision green?
Night Vision is deliberately green in color as shading levels in green are the easiest for the human eye to distinguish. Night Vision used to also be available in red, but scientists later determined that green was easier to see and use.
Can I export night vision?
No. Not without a proper license from the US State
Department or the Department of Commerce.
- Export of GEN-2
night vision equipment from the United States without a
valid export permit issued by the U.S. Department of Commerce
is strictly prohibited and is a federal crime.
- Export of GEN-3
night vision equipment from the United States without a
valid export permit issued by the U.S. Department of State,
Office of Defense Trade Controls is strictly prohibited and
is a federal crime.
- It is the Buyer's responsibility to request
and obtain export licenses for the export of the subject items,
and to ensure that the requirements of all applicable laws,
regulations and administrative policies are met.
Can't find the answer to your Question?
See also: Night
Vision Terminology and Definitions - Generations
and: How to Buy Night Vision Equipment
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a Night Vision Expert page.
