What are black spots?
Black spots are cosmetic blemishes that may originate from fixed tiny particles inside the Image Intensifier Tube (IIT) or in the fiber optic of the screen. Small size black spots are inherent to the manufacturing process and do not affect the performance or reliability of the device. Black spots can be acceptable as long as they don’t interfere with the viewing of the image to be observed and therefore specifications of tubes should be fine-tuned to match the constraints of the end-use application.