Back in 1911, Wollensak Optical Co. of Rochester, New York introduced the Velostigmat Series II f 4.5 variable diffusion lens for a variety of large format sizes. This lens accompanied the convertible Velostigmat Series Ia in that same catalog. In the mid-1930s, a wide-angle Series III was also introduced and the Velostigmat became truly cemented in photographic history.

Wollensak went on to produce Velostigmat designs for 35mm, cinema and medium formats - and these lenses were often included in shutters that were also made by Wollensak, which had their own awesome names: Alphax, Betax, Gammax and Deltax, and later the ubiquitous Rapax.

Just like all of the lenses in Serious Glass, the word is interesting by itself. It might not roll off the tongue like Plasmat or sound futuristic like Hypergon or Solinar, it might sound a little bit like a medical condition you should get checked - but it's got that unique thing that qualifies it to be in this series.