That's almost certainly an achromat unless you got a screaming deal I want to know about. It's not in the same league optically as the Canon lens, which is more like an apochromat, even though you'd probably be disappointed using the Canon lens as a visual telescope - it will be tough getting and keeping sharp focus on stars with the Canon. They had to use a feedback control system on the focuser in the early paper. They also use a lot of image processing.
Also they're not so much using the speed of the lens for shorter exposure times but for field of view and for high sensitivity.
In general photographic lenses make mediocre telescopes and telescopes make mediocre photographic lenses - try using one of your tubes for some terrestrial photography to see. So it's pretty amazing that the Canon lens performs so well to begin with, that they're able to use it like a fast apochromat, and even more so that they're able to build it out to be roughly equivalent to a really large apochromat. With eight lenses, the early paper claims the instrument is equivalent to a 40cm f/1 refractor. How would you build such a thing? Well, this is how.
Also they're not so much using the speed of the lens for shorter exposure times but for field of view and for high sensitivity.
In general photographic lenses make mediocre telescopes and telescopes make mediocre photographic lenses - try using one of your tubes for some terrestrial photography to see. So it's pretty amazing that the Canon lens performs so well to begin with, that they're able to use it like a fast apochromat, and even more so that they're able to build it out to be roughly equivalent to a really large apochromat. With eight lenses, the early paper claims the instrument is equivalent to a 40cm f/1 refractor. How would you build such a thing? Well, this is how.