Night Vision Products

Order your night vision

Here's how Night Vision imaging enhancement works: A conventional lens, called the objective lens, captures ambient light and some near-infrared light.

The gathered light is sent to the image-intensifier tube. In most Night Vision Devices, the power supply for the image-intensifier tube receives power from two N-Cell or two "AA" batteries. The tube outputs a high voltage, about 5,000 volts, to the image-tube components.

The image-intensifier tube has a photo cathode, which is used to convert the photons of light energy into electrons.

As the electrons pass through the tube, similar electrons are released from atoms in the tube, multiplying the original number of electrons by a factor of thousands through the use of a micro channel plate (MCP) in the tube. An MCP is a tiny, glass disc that has millions of microscopic holes (micro channels) in it, made using fiber-optic technology. The MCP is contained in a vacuum and has metal electrodes on either side of the disc. Each channel is about 45 times longer than it is wide, and it works as an electron multiplier.

When the electrons from the photo cathode hit the first electrode of the MCP, they are accelerated into the glass micro channels by the 5,000-V bursts being sent between the electrode pair. As electrons pass through the micro channels, they cause thousands of other electrons to be released in each channel using a process called cascaded secondary emission. Basically, the original electrons collide with the side of the channel, exciting atoms and causing other electrons to be released. These new electrons also collide with other atoms, creating a chain reaction that results in thousands of electrons leaving the channel where only a few entered. An interesting fact is that the micro channels in the MCP are created at a slight angle (about a 5-degree to 8-degree bias) to encourage electron collisions and reduce both ion and direct-light feedback from the phosphors on the output side.

At the end of the image-intensifier tube, the electrons hit a screen coated with phosphors. These electrons maintain their position in relation to the channel they passed through, which provides a perfect image since the electrons stay in the same alignment as the original photons. The energy of the electrons causes the phosphors to reach an excited state and release photons. These phosphors create the green image on the screen that has come to characterize night vision.

The green phosphor image is viewed through another lens, called the ocular lens, which allows you to magnify and focus the image. The Night Vision Device may be connected to an electronic display, such as a monitor, or the image may be viewed directly through the ocular lens.

Frequently Asked Questions

What is the main difference between Generation 2 Night Vision and Generation 3 night vision?
The primary difference between the two Night Vision generations is the photocathode. Generation 2 Night Vision uses a multi alkali photocathode while Generation 3  Night Vision uses gallium Arsenide. Gallium Arsenide provides a significant increase in photo response and tube life. Other differences in performance will be image tube resolution, tube gain and signal to noise ratio. Therefore Generation 3 Night Vision offers greater clarity but is generally more expensive than Generation 2 Night Vision. Generation 2 night vision works well in most situations while Generation 3 Night Vision will achieve high performance in all conditions.

                                                                    Green Night vision - Forest w/ Moon Background
What is Generation 3 Ultra?
Generation 3 Ultra Night Vision is the highest performing image tube in its class. Image intensifier tubes are manufactured for the U.S. Department of Defense under contracts that are designated as OMNIBUS. The current OMNI V contract requires 64 line pair resolution ultra tubes. Most night vision users will find that a 51 line pair image tube will more than meet their needs. Because the OMNI V contract is relatively new, Ultra tubes will command a higher price than other Generation 3 tubes.

Is there a Generation 4?
Yes, the two major night vision image tube manufacturers have developed a generation 4 image tube. The tubes use a film less technology which greatly improves the signal to noise ratio, lower halo, and improved resolution. You'll find we have many Night Vision sites and Night Vision equipment listed with this new Technology.

Can Generation 1 be useful?
Yes, Generation 1 Night Vision can be useful in most nighttime situations. Newer Generation 1 Night Vision devices do offer increased performance from there older predecessors. Generation 1 Night Vision 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.

                                                    Color Night vision - Street View w/ some lighting
 

What can I expect an image tube to look like?
All Night Vision 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 micro channel 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.

Can I export night vision?
Not without a proper license from the US State Department or the Department of Commerce. Please contact us with any questions regarding the export of night vision.

Order your police products and night vision products today!

Order your night vision