Sorry about double posting, just realized ATM might be a better place for my questions than the refractors forum.
My current understanding is that this lens is Undercorrected with a Positive SA, which creates an airy disk (simulated probably, left to right=intra-focus to extra-focus) as shown. Is this correct? Because I have seen multiple posts on CN and even academic pdfs either calling this overcorrected or saying that a negative SA is associated with undercorrected lens. For example, from telescope optics site (https://www.telescop...aberrations.htm ): “spherical aberration is " overcorrected", i.e. with marginal rays crossing before paraxial rays” (sorry if I misunderstood, but this should be Undercorrected, right?)
Edited by flywing1, 03 December 2021 - 07:12 PM.