UPDATE: updated graph  see below. I've coaxed Excel into doing a quadratic leastsquares fit instead of linear, and zoomed in on the region of most interest. FWIW the curves are automatic in Excel, not of my doing.
I was interested because previously from the Russian examples I had guessed a few rough approximations, as follows:
PV 0.30 (⅓ wavelength) ~ Strehl 0.90
PV 0.25 (¼ wavelength) ~ Strehl 0.94
PV 0.16 (1/6 wavelength) ~ Strehl 0.95
PV 0.12 (1/8 wavelength) ~ Strehl 0.98
Though it's only a rough correlation as pointed out before, eg a turned edge vs a central hump.
Last edited by Wavytone; 01092019 at 08:06 PM.
