by Matt Tarlach
First time in a while I've used decent aperture (6" Newtonian) on our Moon, and what a difference over the 80mm refractor! For example: The eastern segment of the Hyginus rille was revealed as am obvious crater chain, even several degrees from the terminator....I was pretty proud of eking this observation out of the 80mm under ideal lighting. With the 80mm I was often straining to see the finest details drawn by Rukl; with the 6" I was obviously seeing much finer detail than depicted in his excellent atlas.
Very good looks at Autolycus, Aristillus, and Archimedes right on the terminator, impressive terracing about the latter and rays surrounding Aristillus. Piton was interesting, with a suggestion of a terrace about halfway up the mountain on the eastern face. Ptolemy under low light revealed an uneven floor, recalling sea swells. Had hoped for good view of Alphonsus but most of the floor remained in shadow until moonset.
Not much really interesting to report but had to post on the impressive gain in resolution with the larger aperture. My 80mm is an f11 Vixen with excellent optics; it routinely outresolves Prontos and Rangers on high and low contrast detail. The 6" newt is an f8 that star tests at around 1/4 wave (maybe spherical), not bad but no great shakes, yet it absolutely spanked the 80mm. So much for quality refractors beating superior aperture, in case anyone was still wondering.
Hope I can finish my chores in time to view again tonight!