Author: Created: 2/10/2012 10:47 AM RssIcon
"The Nightlight" by Eyes on the Sky is all about how to see things in the night sky, things you can build to improve your amateur astronomy experience, and general thoughts on astronomy and light pollution.
By Dave Fuller on 11/28/2012 9:06 PM
My parents visited for the Thanksgiving weekend.  My dad helped me finish putting together my prototype 6" f/10.9 reflector telescope.  The tubes had been taped and shellacked.  The secondary spider was completed.  The primary cell had been purchased.  And the mirror had just been refigured and coated.  So everything was basically in place; it just needed to be put together.

With a few holes drilled in the tube, I got the spider and secondary in place.  Three more holes and I had the primary mirror cell all set.  I used a laser collimater to align the two together, and having attached a 13" long dovetail bar to the two tubes using some 1/4-20 screws and bolts, I slapped the whole thing on my SkyViewPro mount / pier.

In went a 25mm eyepiece.  Now, given that it was dark, I hadn't aligned the finderscope with the main tube.  So even finding the Moon was an exercise in some frustration, initially.  When I'd finally got the Moon in the main scope, I adjusted the finder.  Even with the lower power eyepiece,...
By Dave Fuller on 11/17/2012 6:55 PM
Skywatcher apparently has a rebranded version of these scopes.  Someone on Reddit.com/r/astronomy asked why they were having trouble using a 3x barlow with it.  Apparently, this person couldn't get the telescope to focus using it, and wondered why.  Given the short focal length, it's not a bad idea to be using a barlow with this scope, in order to get sufficient magnification to view planets.  But, I don't have a 3x barlow.  I only own a 2x Shorty barlow and a Meade #140 full length 2x barlow.  So I thought it might at least be helpful to see about trying both of my barlows in my Funscope to see what happened.
By Dave Fuller on 11/12/2012 7:44 PM

Curved vane spider on template

Reflectors always seem to pose a challenge to the visually obsessed among those in the amateur astronomy community.  Unless you are building a Herschelian or offset-axis reflector - in other words, one with no central obstruction - then there is always the problem of the best way to place that obstruction in the light path with as little diffraction occurring as possible.  Some don't mind the straight, four or six diffraction spikes caused by typical 4-vane or 3-vane spiders, and to be honest, they don't really bother me all that much.  In fact, that may be the direction I go.  But something that has intrigued me for quite a long time is the curved spider.  Oh, believe me, if I could figure out a way to afford an optical window for my reflector, I wouldn't hesitate.  So the curved spider is the next best thing.

What is a "curved spider" you ask?  Glad you did.

By Dave Fuller on 11/8/2012 8:32 PM

Mirror Cells: University Optics and Meridian Telescopes

Two 6

A review of two mid-cost mirror cells for reflector telescopes.

By Dave Fuller on 11/5/2012 12:13 PM
Comet Hergenrother breaking upcouple weeks ago "Eyes on the Sky" highlighted the path of Comet Hergenrother as it passed through Pegasus, given that the comet had unexpectedly brightened from a barely-visible 15th-magnitude to a visible-in-many-small-scopes 10th-magnitude.  Now it appears a bit more obvious why...


Photo courtesty of NASA / JPL-Caltech / NOAO / Gemini

By Dave Fuller on 11/4/2012 8:58 AM
I got my December issue of Astronomy Magazine the other day.  Towards the back I started reading an article about light pollution, and i was thinking, "Oh noes... I hope it doesn't just retread over the same old ground."  But it didn't: I was pleasantly surprised to read that it wasn't just talking about the problem and lamenting the loss of dark skies, it was actually offering practical tips on light pollution reduction, like how to talk to neighbors about the problem - tactfully, since "light at night" can be an emotional issue related to fear / security.  It also addressed how to retrofit existing lighting, so one need not buy all new lights to improve those already in place.

On my own house, I've changed - or removed - almost every outdoor light already.  We no longer have a "post lamp" at the end of our driveway (helped by the fact that my wife kept bumping it with her car and the metal fatigued to the point where it fell over).  I had long ago swapped out the light over our garage door to one that...
By Dave Fuller on 11/2/2012 5:54 PM

I'm always a little hesitant to work on a new telescope when it means taking apart another one.  The 6" f/5 tube I've been working on - well, I got some finderscope shoe mounts in the other day.  Nice anodized aluminum ones from Scopestuff, and they came with the mounting screws AND there was no additional cost for shipping.  Come to think about it....

By Dave Fuller on 11/1/2012 8:25 PM

A question often asked on beginner forums or on reddit astronomy boards is, "What telescope should I get?" or "What is the best beginner telescope?" There's a helpful - if older - article from 2010 by Sky and Telescope that covers some (at the time) sub-$100 telescopes, all of which are more than that now by $10 to $30.  That's a good place to start.  But sometimes the budget is more (or less!).  So what to do from there?  There are SO many choice today, it's hard to know what to get.  Here are some recommendations I think may help.

By Dave Fuller on 10/31/2012 11:47 AM

I've been at a crossroads on what spider to build for a couple 6" reflectors I'm either building or redesigning.  I like the idea of a curved vane spider, though buying or making one is a bit more expensive or involved.  And straight vane ones don't particularly bother me, but when I do outreach, I am sometimes asked about the "spikes" near bright stars or planets.

I bought a 4 vane straight spider a few weeks ago.  It's okay - an old Meade one.  It will work, if necessary.  I'm considering building a modified version of the Royce spider, though perhaps sans adjustment screw (I'll just bend the brass tube to collimate).  I'm a believer in the KISS principle - Keep It Simple Stupid.  

The curved vane gets good reviews in general from people who use them - though it has detractors, who suggest

By Dave Fuller on 10/29/2012 9:39 PM
No, no libations (though the Wisconsin Amber I had was quite tasty).  No, I figured I would pop outside for a moment and catch the just-barely-past-full Moon tonight.  Took a simple 70mm Meade refractor and - what's this?  Are those 'edge of the Moon" mare I see?  Why yes, indeed!  I spotted Mare Australe initially, then after I snapped a few (mostly bad - there are some high clouds that made the shots look poorer than I could see with my eye) pictures with my cellphone camera, I noticed I had also managed to see Mare Smythi and Mare Marginis. These are not "always seen" mare, as the Moon must be 'tilted' the correct direction for us to see it - a phenomenon known as libration.  Anyway, I thought I'd share the picture I got, bad as it is.

The Nightlight

This blog includes what to see in the night and daytime skies, thoughts on telescopes, binoculars, and other astronomy observing accessories and equipment, plus my own occasional notes on objects I've seen and observed. Oh, and the random theater or other "my take on life" post. In other words, there is always something interesting. Check it out.