EP33

The EP33 is a generation 0+ image intensifier tube of Russian origin.[1] There are multiple variants of the EP33, these are: EP33, EP33-U, EP33-UD, EP33-US-D and EP33-SF. The SF is special, as it has a spherical photocathode to counteract distortion.[2] These tubes were and still are widely used in civilian devices marketed as "generation-1".