5mm's on Cassini

Taking advantage of a break between storm fronts, I put my TV-102 on the moon tonight to compare the views through a 5mm UOHD vs. a 25mm UO ortho/5x Powermate combination. Conventional wisdom and theory says the fewer elements the better, but on Cassini every time I looked through the 5mm I could make out the crater and Cassini A within it, and whenever I switched to the 25mm/Powermate combo Cassini B would pop out. Every time I switched eyepieces, the same result. Anyone out there have a comment or an insight to help me understand this?

Larry Seguin

I can't explain it Larry. But when the storm fronts passes, I usually get very transparent sky but lousy seeing. So how was the seeing? If it's poor, I'd wait for a better seeing to make a comparison.

Nevertheless, 5mm gives you 176x. Cassini B is a large crater, visible at much lower power and thus should have been visible in both eyepieces. If you want a good test for the TV-102, try some of these teeny features (such as the dome or craterlets around the area).
http://members.cox.net/ronby/Solar-System/Moon-Cassini-Dome-070603.htm
Since I got my new fabulous moon book, I've also learned that there are 3 hills between A & B (my TV-102 Light Cup has shown me the largest one so far)!

Ron B[ee]