An image intensifier boosts the intensity of the incoming light. By converting photons to electrons and back to photons, the light intensity can be increased significantly. Another feature of an image intensifier is that it can act as an ultra-fast shutter.
The relay optics of HiCATT and TRiCATT project the output of the image intensifier onto the sensor of your camera. This calculator helps you determine the optimal configuration of image intensifer diameter and relay optics for your camera and application.
The photocathode is the entrance of the image intensifier. This is where the incoming photons are converted to electrons. The quantum efficiency of the photocathode material specifies how efficient this conversion is for each wavelength.
The output of the image intensifier contains a layer of phosphorescent material. Upon impact of an electron, the phosphor screen will emit light. Depending on the type of phosphor, the intensity of the emitted light will decrease faster.