Tube generations
Labels like Gen 1, Gen 2+ and Gen 3 that group night vision tubes by design. They are a rough guide; the measured specs say more than the label.
What it means
Night vision tubes are grouped into generations by how they are built:
- Gen 1: the oldest design, with no microchannel plate. Needs more light, and the picture is often soft or distorted toward the edges. Cheap.
- Gen 2: adds a microchannel plate, a disk that multiplies the signal. A big step up in brightness and clarity.
- Gen 2+: a common sales label for improved Gen 2 tubes. It is not a formal standard, and performance varies widely under it.
- Gen 3: uses a gallium arsenide photocathode, a more sensitive light-catching coating, and usually a thin protective film on the microchannel plate. Variants with the film thinned or removed are sold as thin-filmed or filmless.
Why the label is not enough
The civilian market has no single referee for these labels. Sellers add their own terms, such as “high performance”, and some European tube makers do not use the US generation names at all, describing tubes by measured performance instead. A strong Gen 2+ tube can rival a weak Gen 3 tube on paper.
That is why buyers compare figure of merit, resolution and signal-to-noise ratio, and check how each figure is stated.
What it changes in the field
In general, newer generations see more in less light, with a cleaner picture and longer life. For a hunter, Gen 2+ and Gen 3 tubes are the practical range. Gen 3 tubes made in the US are export controlled; see ITAR.
How we use it on this site
We record the maker’s own wording, such as “Gen 3 filmless”, and file it under a plain generation where it maps cleanly. We do not rank tubes on the label alone.