Halo value is a metric not often discussed. Halo in a simple sense refers to the amount of “halo” effect seen around a light source viewed through an image intensifier. A large halo will tend to white out or wash out the image in the area of the light source.Now that we know what halo is in a pra...

Before we dive into a quick synopsis of tube types it’s important to understand these are minimum qualifying characteristics or metrics. Tubes of all types regularly exceed their minimums. These serve as only a baseline representation point of reference. PHOTONIS DEFENSE Photonis Commercial: A t...

EBI (Equivalent Background Illumination)    EBI is a metric of noise and can be thought of as that, equivalent background noise. A condensed version is - a measured low light base noise level minus no light base noise level. This gives you your end noise value, or EBI. 2.5 is the MIL-SPEC maximu...

  Tube Options:   Photonis Echo: These tubes are most closely related to Gen 2 by US definition due to the lack of GaAs (gallium arsenide - a semi conductor), though technically they’re a hybrid technology as they utilize a multi-alkali photocathode. Whereas Gen 2 of the "old days" used a bi-alka...

“Blem” and “Dark Spots.” What do they mean?Dark Spots:Dark spots are inherent to the manufacturing process. Could be a particle sandwiched in the intensifier, fiber optic, or various other circumstance. All tubes are allowed dark spots. This is why there is a prescribed dark spot allowance. Dark ...