From: someone@anywheret.net   
      
   "JimD"  wrote in message news:2016102421540897537-email@nowherecom...   
      
   > To clean the mirrors, I managed one make small, ok, tiny, scratch along   
   > the outside edge of the big mirror.  That's ok. I was curious how   
   > difficult or easy it would be to scratch it. Now I know, and without   
   > ruining anything on an expensive one :-)   
      
   A soft cloth would make it safer. It's very easy to scratch an optical   
   surface, particularly the aluminum or other coating applied to it if it's   
   the mirror of a reflector.   
      
   > They were pretty dusty / cruddy when I got it. Cleaned up beautifully.   
      
   If it was very dirty, it would be a good idea to remove it f rom its cell,   
   put a film of dishwashing detergent on it and run warm water on that. That's   
   a technique I often use for CDs that are all messy, because theirs is an   
   optical surface too. Once the detergent is on, it also helps to *very   
   gently* run the palm of your hand over the  detergent film ONLY, being *very   
   careful* Not to actually touch the optical surface. After the rinse, it'll   
   be very clean and can then be *carefully* laid on a soft clean dishcloth   
   *without moving* it, in order to absorb any remaining water on the surface.   
      
   > I went thru some alignment stuff today.  Have it in pretty good shape.   
   > I'm basically taking everything on this apart, just to see how it's built.   
   > " Curious, I am "  - said in a Yoda voice ;-)   
      
   Collimating the telescope and/or checking it has to be done anyway.   
      
   > It is far brighter than my biggest refractor. A lot brighter.  And without   
   > all the chromatic fringing of glass lenses.   
      
   Any decent refractor will have an apochromatic objective lens, corrected for   
   both chromatic and spherical aberration...but the cheap ones are quite   
   another matter, and that even includes binoculars...hard to believe some of   
   the JUNK out there even today with improved optical technology and cost   
   cutting manufacturing techniques!   
   Of  course it's brighter, because its aperture is bigger, because refractors   
   are just  sooooooo expensive. A 4.5" refracting scope will easily cost   
   thousands...Meade has a 5.1" (130mm) f/7 refractor for $2,999.00...beautiful   
   scope for less than I would have expected ;)   
      
   > I bought this one to rescue it from an eventual trip to the trash bin.   
      
   What a way to look at it ;) Or as the old saying goes regarding telescopes,   
   particularly with regards to any sleeks and/or scratches they may have on   
   their optical surfaces - one does not look *AT* the  telescope, one looks   
   *THROUGH* it! ;)   
      
   > The thrift shop barely knew what it was. Someone had broken the tripod,   
   > and the eyepiece lenses were missing.  Oh well, it has a home now :-)   
      
   > And eventually there'll be a clear sky.  Moonrise is around 1:30 am this   
   > morning.   
      
      
   Jim   
      
   Yeah, and with the frozen but very clear winter nights with all that  stable   
   air to minimize atmospheric aberration, to come...it'll bring back such fond   
   memories of younger days of freezing at the homemade 8" f/8 Newtonian   
   reflector on the 3rd floor open back porch of our Chicago apartment back   
   when light pollution was nothing as horrible as it is now...of 'hopping'   
   around  the sky from one object to another using the setting  circles and   
   the celestial coordinates in A Field Guide To The Stars And Planets and/or   
   Norton's Star Atlas...my father even had a sidereal clock I could look   
   through the  kitchen window to see for keeping the settings accurate, along   
   with a bunch of homemade sugar cookies to munch on, which I only handled   
   with my left hand because the right was for adjusting the telescope ;) Made   
   it a little more  pleasant to observe, eat cookies, and  freeze than to only   
   observe and freeze ;) But those  were really the good old days...and I'd   
   like  them back...IF I can get something  decent to observe with.   
      
   In any case, the usual closing to another astronomer,   
      
   Good  Seeing!   
      
   Ouisie   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)