I've read more than once on CN that the "V" should form an arrow pointing to the sky, though I like the logic of the opposite way. This last convention should be easy enough to check in the case of say, an achromat.
Just for reference, there is a great illustration floating around (I'm sure everyone has seen it) showing 1 correct and 7 incorrect ways to re-assemble an achromat. I don't know who the originator is, but some of us owe that person a debt of gratitude.
Found it! Sometimes it is hard to distinguish the difference between cases 1 and 2 by simply examining the elements (the curves are nearly the same). Case 1 produces a far better star image!
Edited by Tenacious, 27 February 2021 - 11:19 AM.