Richard Crisp said:
"Hey lenticular clouds or lenticular galaxies, they are all lenticular and
on
a rainy full moon weekend who cares about the difference? "
Truer words were never spoken!
I gotta admit, I actually rather like rainy full moon weekends. It gives me
a chance to work on projects. I was supposed to be caving up in the Sierra
this weekend, but snowy roads put the kibosh on that idea. So, I'm in town,
fiddling around with projects - and procrastinating on the grading that I'm
supposed to be doing.
I think I'm going to take my Russian Maksutov apart and put it back
together. It's a great scope, and gives great lunar views, but there's
always been something a bit lacking on the planets. There's a slight
'crispness' to the limbs of planets that I don't quite see, but which I
suspect should be there, because I see it in other scopes. At high
magnification there's a slightly 'trefoil' appearance to the stars'
diffraction rings. I've always attributed this to thermal issues, but now
I'm beginning to suspect that there's a pinched optic somewhere. Methinks
that a good "take apart, re-assemble, re-collimate" weekend is in order. If
I'm right, and if I can get rid of the trefoil aberration, it'll be
'refractors beware' time. Maybe I'll even be able to bag that little summit
crater on Mons Gruithuisen Gamma at long last.
I'm also making 3-D anaglyph maps this weekend. I recently learned about an
amazing filter in Photoshop (Filter > Distort > Displace) that allows one
to create the right-eye and left-eye images for an anaglyph version of a
topographic map, if one has a matching digital elevation model.
(I learned about this from some guys at the University of Minnesota. They
have some great anaglyphs at http://www.nced.umn.edu/Maps.html , including
a nice Mars water features map.)
I think that we could use this to make 3-D star maps, too. Imagine a star
atlas with black stars on a white background. If we could find a way to
make the stars shades of gray, with different shades corresponding to their
distances, then it might be easy to make stereo star maps. Hmm, maybe Wil
Tirion needs to hear about this...
Marek
Received on Sat Apr 23 12:27:19 2005