The FOM, or Figure of Merit is a number calculated by multiplying the Signal-to-noise ratio by the resolution of an image intensifier. The FOM number allows a quick estimate of the general performance level of that image intensifier. Every order will come with spec sheet for the image intensifier tube that states that tube’s characteristics and its compliance with advertised specs.
2. Green V.S. White Phosphor
There is no scientific evidence that one phosphor color is better than another. Everyones’ eyes are different and systems are used in diverse environments. It comes down to user preference.
3. Generations
Gen I: Developed in the 1960s, Gen I systems utilized the basic principles which will amplify the existing light several thousand times letting you clearly see in the dark. These Gen I systems provide a bright image, however they are not very clear or distinguishable. Gen I lifespan 1000 hours.
Gen II: Developed in the 1970s, Gen II offered a substantial increase in performance over Gen I systems. This performance enhancement was obtained by 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. Gen II lifespan 2000 to 4000 hours.
Gen III: Developed in the 1980s, Gen III systems offer the highest clarity and performance in extreme darkness that is currently available. Gen III systems use a gallium arsenide photocathode film to increase their performance over Gen II systems. In the last 10 years or so, Gen III systems have had upgrades such as thin films and gated power supplies (Pinnacle) incorporated into them, which have even further enhanced the performance of Gen III tubes. This makes them the highest performance image intensifiers currently available. Gen III lifespan 12,000+ hours.
Gen IV: When upgrades were made to Gen III tubes, such as gated power supplies and the use of un-filmed or thin filmed photocathode, the manufacturers sought to label these enhancements as Gen IV image intensifiers. However the Department of Defense did not see these enhancements as substantial enough improvements for the creation of a new Gen IV category. Nonetheless some companies still try to use the Gen IV moniker as a marketing ploy to charge more for the same exact Gen III image intensifiers that are already currently available at a substantially lower cost from other manufacturers.
