31-07-2012, 04:54 PM
Night Vision Technology
night vision technology.ppt (Size: 1.53 MB / Downloads: 49)
Definition
Night vision is the ability to
see in low light conditions.
As the name suggests, it is the expertise that makes us capable to see in the night without using any external light source(such as a torch or a lamp). It is the technology that provides us with the miracle of vision in total darkness and the improvement of vision in low light environments.
History
Night Vision technology has been under research since Pre-World War II. However, a defined shape came post World War II, i.e., in early 1950s, by the U.S. Department of Defense primarily for defense . This is when Generation-0 for Night Vision was developed. Devices of this generation were bulky and expensive.
Humans have poor night vision
Humans have poor night vision compared to many animals, in part because the human eye lacks a tapetum lucidum(which is a biologic reflector system that is a common feature in the eyes of vertebrates).
Ranges
Human vision is confined to a small portion, i.e. range of the electromagnetic spectrum called visible light.
Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range.
Intensity range
Sufficient intensity range is simply the ability to see with very small quantities of light.
Many animals have better night vision than humans do, the result of one or more differences in the morphology and anatomy of their eyes. These include having a larger eyeball, a larger lens, a larger optical aperture (the pupils may expand to the physical limit of the eyelids), more rods than cones (or rods exclusively) in the retina, a tapetum lucidum.
night vision technology.ppt (Size: 1.53 MB / Downloads: 49)
Definition
Night vision is the ability to
see in low light conditions.
As the name suggests, it is the expertise that makes us capable to see in the night without using any external light source(such as a torch or a lamp). It is the technology that provides us with the miracle of vision in total darkness and the improvement of vision in low light environments.
History
Night Vision technology has been under research since Pre-World War II. However, a defined shape came post World War II, i.e., in early 1950s, by the U.S. Department of Defense primarily for defense . This is when Generation-0 for Night Vision was developed. Devices of this generation were bulky and expensive.
Humans have poor night vision
Humans have poor night vision compared to many animals, in part because the human eye lacks a tapetum lucidum(which is a biologic reflector system that is a common feature in the eyes of vertebrates).
Ranges
Human vision is confined to a small portion, i.e. range of the electromagnetic spectrum called visible light.
Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range.
Intensity range
Sufficient intensity range is simply the ability to see with very small quantities of light.
Many animals have better night vision than humans do, the result of one or more differences in the morphology and anatomy of their eyes. These include having a larger eyeball, a larger lens, a larger optical aperture (the pupils may expand to the physical limit of the eyelids), more rods than cones (or rods exclusively) in the retina, a tapetum lucidum.