How night vision works

Night vision products are light amplifying devices. Light amplification is less expensive than thermal, however, higher-end and more effective night vision tubes can become more expensive. Light amplification technology takes the small amount of light, such as moonlight or starlight, that is in the surrounding area, and converts the light energy (scientists call it photons), into electrical energy (electrons). These electrons pass through a thin disk that's about the size of a coins and contains over 100,00,000 lakh channels. As the electrons travel through and strike the walls of the channels, thousands more electrons are released. These multiplied electrons then bounce off of a phosphor screen which converts the electrons back into photons and lets you see an impressive night-time view even when it's really dark.

more   video

Thermal vision optics

Thermal imagers are instruments that create pictures of heat rather than light. They measure radiated IR energy and convert the data to corresponding maps of temperatures.


Military optics

SAPPL manufactures Director Fire control No. 7 MK-5, Board Plotting Arty (PUo-9) Cased l01A, Compass Prismatic Liquid, optical test equipment, Range Finders, Boresights, Borescopes, Dioptometers, etc. We are registered with DGQA for the manufacture and supply of 34 instruments.

We have the ability to work with a variety of metals. SAPPL offers in-house Research & Development, Mechanical Manufacturing, Product Assembly & Quality Assurance (ISO 9001:2008). Our fabrication machine and a climate-controlled plant assure adherence to strict precision and performance standards.

Thermal Vision Optics

Thermal imagers are instruments that create pictures of heat rather than light. They measure radiated IR energy and convert the data to corresponding maps of temperatures. Today, instruments provide temperature data at each image pixel and, typically, cursors can be positioned to each point with the corresponding temperature read out on the screen or display. Images may be digitized, stored, manipulated, processed and printed out.

All objects have a certain temperature and emit waves of energy called infrared radiation. Hot objects emit more energy than cold objects. A thermal imager translates these energy waves into a viewable image, which shows a "heat picture" of a scene. The pictures above demonstrate the difference between visable light what the naked eye can see and a thermal image. Move your cursor over the images and you will notice the change between the visable and thermal images.

Types of Thermal Imaging Devices

Most thermal-imaging devices scan at a rate of 30 times per second. They can sense temperatures ranging from -4 degrees Fahrenheit (-20 degrees Celsius) to 3,600 F (2,000 C), and can normally detect changes in temperature of about 0.4 F (0.2 C).

There are two common types of thermal-imaging devices:

  • Un-cooled:
    This is the most common type of thermal-imaging device. The infrared-detector elements are contained in a unit that operates at room temperature. This type of system is completely quiet, activates immediately and has the battery built right in.
  • Cryogenically cooled:
    More expensive and more susceptible to damage from rugged use, these systems have the elements sealed inside a container that cools them to below 32 F (zero C). The advantage of such a system is the incredible resolution and sensitivity that result from cooling the elements. Cryogenically-cooled systems can "see" a difference as small as 0.2 F (0.1 C) from more than 1,000 ft (300 m) away, which is enough to tell if a person is holding a gun at that distance!

While thermal imaging is great for detecting people or working in near-absolute darkness, most night-vision equipment uses image-enhancement technology.