EthosPosted By Bill Burghardt |
IIRC, at NEAF, Al said with the various powermates available, not too many focal lengths would be necessary.
Posts Made By: Bill Burghardt
July 29, 2007 04:48 AM
Forum:
Eyepieces
August 14, 2007 08:51 PM
Forum:
Equipment Talk
Strehl best way to describe optical wavefront ?Posted By Bill Burghardt |
Doug Peterson said:
I think so.
Most people do not relate to waves peak-to-valley (PV) or waves RMS (much more meaningful, but numerically 3-5 times smaller).
The Strehl on the other hand--the actual peak intensity of a star (or point spread function if you want to impress people) as a fraction of the theoretical maximum--is something you can see at the eyepiece.
And numerically it is easy to relate to:
80% or 0.8 of 1.0 is nominally diffraction limited. Remember when 80-89% got you a B in school?
90-100% got you an A.
And 95% and above got you a A+.
Your thoughts on this most pressing matter?
Wish it had been that EASY! 84-93 was a "B", 93-100 was an "A", at least in the high school I attended!
August 16, 2007 09:07 PM
Forum:
After Dark
Night encounters?Posted By Bill Burghardt |
CRUNCH, CRUNCH.
Well, something like that, about 20 feet from the observatory one night. We have the black bears roaming around all the time, just not this close.
Other guy got in his car for protection, I had about 250 watts of driving lights, so thought I would see what was there.
Slight embarrassment, it was SO quiet that evening, the poor young opossom walking through the dry leaves sounded like a much bigger animal.
Good laugh, after shutting off the lights and readjusting to the dark we got several hours of clear skies and great viewing.
Well, something like that, about 20 feet from the observatory one night. We have the black bears roaming around all the time, just not this close.
Other guy got in his car for protection, I had about 250 watts of driving lights, so thought I would see what was there.
Slight embarrassment, it was SO quiet that evening, the poor young opossom walking through the dry leaves sounded like a much bigger animal.
Good laugh, after shutting off the lights and readjusting to the dark we got several hours of clear skies and great viewing.
August 16, 2007 09:11 PM
Forum:
Equipment Talk
DD-1 is hot!Posted By Bill Burghardt |
IIRC, the original battery pack is six AA cells, 9 volts. Other discussions on these type controllers seem to indicate they do not like too much voltage, and tend to instantly self distruct is polarity is not correct.
FWIW
FWIW
August 19, 2007 05:46 PM
Forum:
Equipment Talk
Porter garden telescope reborn--pricey?Posted By Bill Burghardt |
IIRC, the Stellafane site has a link to another party reproducing a model of the instrument, at a much more realistic price!
FWIW
FWIW
August 20, 2007 05:29 PM
Forum:
After Dark
Night encounters?Posted By Bill Burghardt |
Not astronomy related, but driving home from work Saturday night this HUGE black thing crossed the road in front of me.
Hit the high beams and the LARGEST, nearly all black, skunk I have ever seen ran into the bushes! ONE SMALL white spot on the tip of its tail!
Hit the high beams and the LARGEST, nearly all black, skunk I have ever seen ran into the bushes! ONE SMALL white spot on the tip of its tail!
August 20, 2007 05:31 PM
Forum:
Birding Optics and Photos
Incoming!!! (Black-chinned Hummingbirds)Posted By Bill Burghardt |
The interaction between the birds is fascinating! Great shot.
August 20, 2007 05:52 PM
Forum:
Insects - Flowers and Other Small Stuff - Photos
Mantis and MoonPosted By Bill Burghardt |
WILD! 
August 20, 2007 06:47 PM
Forum:
AstroMart FAQ
Low-ball offersPosted By Bill Burghardt |
Print a map locating the local WallyMart and wish them great happiness with their purchase! 
August 22, 2007 07:44 PM
Forum:
ASTRONOMY
Future of visual astronomy?Posted By Bill Burghardt |
No question that a GOOD piece of electronics can produce a beautiful image to enjoy.
HOWEVER, I prefer to say I saw the faint fuzzy with my own eye (Boo Hiss on binoviewers! )
HOWEVER, I prefer to say I saw the faint fuzzy with my own eye (Boo Hiss on binoviewers!
)
Funding Member
