Time spent looking at the stars is added to your life Bashful, Misty, and little Ralphie - my heavenly stars
A-P 105 Traveler ~ TEC 140 ED ~ TEC 6 MCT ~ XT10 (Zambuto) A-P Mach1 GTO ~ Losmandy GM-8 ~ TV Gibraltar
Jeff -----TEC 140, Stellarvue SVR90T, SV115T20 and AT65EDQ refractors,Webster D14, C11 EdgeHD Lunt LS60THa solar scope double stacked with LS60FHaTelevue Pan 41; Ethos 21, 17; Nagler 31T5, 9T6, 7T6, 5T6, 3.5T6; Delos 10, 12, ES25, 14, 9Astro-Physics 900GTO with Rob Miller Tri36M TripodDM-4 Mount-Extension-Tripod w/ Sky CommanderDM-6 Mount-Losmandy Adapter/Extension-Berlebach Planet w/ Argo Navis
Others may disagree. Your millage may vary. Void where prohibited by law.
edit: I just noticed the graph is at the link the OP posted under "EdgeHD back focus vs spot size"