A Night Vision Device can be either a 1st, 2nd, 3rd or 4th generation unit. What this stands for is what type of image intensifier tube is used for that particular device; the image intensifier tube is the heart and soul of an NVD.
1st generation is currently the most popular type of night vision in the world. Utilizing the basic principles described earlier, a 1st generation unit will amplify the existing light several thousand times letting you clearly see in the dark. These units provide a bright and sharp image at a low cost, which is perfect, whether you are boating, observing wildlife, or providing security for your home. You may notice the following when you are looking through a 1st Gen. unit.
* A slight high-pitched whine when the unit is on.
* The image you see may be slightly blurry around the edges. This is known as Geometric Distortion.
* When you turn a 1st Gen. unit off it may glow green for some time.
* These are inherent characteristics of a 1st Gen. unit and are normal.
2nd generation is primarily used by law enforcement or for professional applications. This is because the cost of a 2nd Gen. unit is approximately $500.00 to $1000.00 more then a 1st Gen. The main difference between a 1st and a 2nd generation unit is the addition of a micro-channel plate, commonly referred to as a MCP. The MCP works as an electron amplifier and is placed directly behind the photocathode. The MCP consists of millions of short parallel glass tubes. When the electrons pass through these short tubes, thousands more electrons are released. This extra process allows 2nd generation units to amplify the light many more times then 1st generation giving you a brighter and sharper image.
2nd Gen. IIT ATNs standard 2nd generation tubes are high quality with exceptional brightness and resolution. Each tube has a micro channel plate, multi-alkaline photocathode with built-in power supply.
2nd Gen. IIT Features:
* Photo Cathode type: Multi-Alkali
* Resolution from 40 to 45 lp/mm
* Signal-to-Noise Ratio from 12 to 20
* 5,000+ hour tube life
CGT IIT.The CGT type of Image Intensifier tubes are engineered for significantly enhanced performance over current 2nd generation IITs. The CGT IIT is a Multi-Alkali compact 18mm format MCP Image Intensifier. Highlights of the CGT specifications are typical SNR of 16-22 and resolution of 45-54 lp/mm. CGT IITs are sensitive in a wide spectral band and thus provide good contrast in all scene circumstances.
CGT IIT Features:
* Photo Cathode type: Multi-Alkali
* Resolution from 45 to 54 lp/mm
* Signal-to-Noise Ratio from 16 to 22
* 10,000-hour tube life
HPT IIT HPT tubes are an upgrade of the CGT Generation tube. They are a Multi-Alkali compact 18mm format MCP Image Intensifier. The HPT tube increases sensitivity, resolution, Signal-to-Noise Ratio (SNR), and the Modulation Transfer Function (MTF). These improvements produce an exceptional image clarity and brightness. Most HPT specifications typically are equivalent to standard 3rd generation. Highlights of the HPT specifications are the typical SNR of 22 and resolution of 64 lp/mm.
HPT IIT Features:
* Photo Cathode type: Multi-Alkali
* Resolution from 55 to 72 lp/mm
* Signal-to-Noise Ratio from 16 to 24
* 10,000-hour tube life
3rd generation By adding a sensitive chemical, gallium arsenide to the photocathode a brighter and sharper image has been achieved over 2nd generation units. An ion barrier film was also added to increase tube life. 3rd Gen. provides the user with good to excellent low light performance.
3rd Gen. Standard IIT Our standard 3rd generation image intensifier tubes are of the highest quality. They have a micro channel plate, GaAs photocathode, and a completely self-contained integral high-voltage power supply. These 3rd Generation tubes provide a combined increase in resolution, signal to noise and photosensitivity over tubes with a multi-alkali photocathode. Generation 3 is the standard for the USA military.
3rd Gen. Standard IIT Features:
* Photo Cathode type: Gallium Arsenide
* Resolution 64 lp/mm
* Signal-to-Noise Ratio 22 Typical
* 10,000-hour tube life
3A Gen. Premium select IIT Our 3A Gen. Premium select IITs are the highest quality of our generation 3 IITs. These IITs are hand picked to provide the highest quality and specifications available in our 3rd Gen. line. They have a micro channel plate, GaAs photocathode, and a completely self-contained integral high-voltage power supply.
3A Gen. Premium select IIT Features:
* Photo Cathode type: Thin Film GaAs
* Resolution from 64 to 72 lp/mm
* Signal-to-Noise Ratio 26 Typical
* 10,000-hour tube life
3P Gen. ITT Pinnacle™ ATN Night Vision units with the 3P designation use ITT Pinnacle™ Image Intensifier tubes. The industry leading ITT Pinnacle™ image tubes utilize a gated power supply providing truly outstanding performance in high-light or light-polluted areas, such as urban environments. The Pinnacle™ tube with gated power supply minimizes any “halo” effects. “Halo” is often associated with using night vision devices in an urban area where random street lights are often an issue with early Generation Night Vision devices. Night Vision units with Pinnacle™ tubes have a resolution of 64-72lp/mm and a typical signal to noise ratio of 26. All Night Vision devices utilizing Pinnacle™ Image Intensifier tubes come with ITT data record sheet. Units with Pinnacle™ tubes are not available for export. A signed export compliance and end use statement is required prior to shipping of these units.
*Pinnacle is a registered trademark of ITT Night Vision
3P Gen. ITT Pinnacle™ IIT Features:
* Photo Cathode type: Gallium Arsenide
* Resolution from 64 to 72 lp/mm
* Signal-to-Noise Ratio: 25-30
* 10,000-hour tube life
4th generation Gated/Filmless technology represents the biggest technological breakthrough in image intensification of the past 10 years. By removing the ion barrier film and “Gating” the system Gen 4 demonstrates substantial increases in target detection range and resolution, particularly at extremely low light levels.
The use of film less technology and auto-gated power supply in 4th generation image intensifiers result in:
* Up to 100% improvement in photo response.
* Superb performance in extremely low light level (better S/N and EBI).
* At least triple high light level resolution (a minimum of 36 lp/mm compared to 12 lp/mm).
4th GEN. GATED/FILMLESS IIT ATNs Autogated / Filmless inverting image intensifier tubes improve night operational effectiveness for users of night vision goggles and other night vision devices. The filmless micro channel plate provides a higher signal-tonoise ratio than standard 3rd Gen. IITs, resulting in better image quality under low-light conditions. An Autogated power supply further improves image resolution under high light conditions and a reduced halo effect that minimizes interference from bright light sources. The reduced Halo maximizes the effectiveness of the Night Vision device in dynamic lighting conditions such as those experienced, for example, in night operations in urban areas.
4th Gen. IIT Features:
* Photo Cathode type: Filmless GaAs
* Resolution from 64 to 72 lp/mm
* Signal-to-Noise Ratio from 25 to 30
* Autogated power Supply
* 10,000-hour tube life
With significant improvement in contrast level and in performance under all light conditions, 4th generation represents the top of the line performance in the night vision market.