How Infrared Works:
This method of night vision amplifies the available light to achieve better vision. An objective lens focuses available light (photons) on the photocathode of an image intensifier. The light energy causes electrons to be released from the cathode which are accelerated by an electric field to increase their speed (energy level). These electrons enter holes in a microchannel plate and bounce off the internal specially-coated walls which generate more electrons as the electrons bounce through. This creates a denser “cloud” of electrons representing an intensified version of the original.
The alternative is to use what’s called thermal imaging. Instead of looking for the light that objects reflect, we look for the heat they give off instead. Generally, living things moving around in the darkness are going to be hotter than their surroundings; that goes for vehicles and machines too. Hot objects give off infrared radiation, which is a similar kind of energy to light but with a slightly longer wavelength (lower frequency). It’s relatively easy to make a camera that picks up infrared radiation and converts it into visible light: it works like a digital camera except that the image detector chip (either a charge-coupled device (CCD) or a CMOS image sensor) responds to infrared instead of visible light; it still produces a visible image on a screen the same way as an ordinary digital camera. Other types of thermal imaging cameras use different colors to indicate objects of different temperature—and they’re commonly used to show things like the heat loss from badly insulated buildings.
The final stage of the image intensifier involves electrons hitting a phosphor screen. The energy of the electrons makes the phosphor glow. The visual light shows the desired view to the user or to an attached photographic camera or video device. A green phosphor is used in these applications because the human eye can differentiate more shades of green than any other color, allowing for greater differentiation of objects in the picture.
All image intensifiers operate in the above fashion. Technological differences over the past 40 years have resulted in substantial improvement to the performance of these devices. The different paradigms of technology have been commonly identified by distinct generations of image intensifiers. Intensified camera systems usually incorporate an image intensifier to create a brighter image of the low-light scene which is then viewed by a traditional camera.
Basic dimensions of Spy Net Ultra Night Vision Goggles are 11.9 x 4.4 x 12.4 inches and they weigh around 2,9 pounds. Another great feature of these night goggles is that there is an option to playback the videos on the goggle video screen, or to upload both videos and photos to any PC or Mac and just watch and share everything that has been recorded.