- APM 140mm DOUBLET APO REFRACTOR
- Comparison of the Boltwood II and Sky Alert Cloud Sensors
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- MONO & BINO VIEWING WITH THE BAADER MORPHEUS 17.5MM EYEPIECE
- The Eye of the Flak (Das Auge der Flak)
- COMPARING THE MASUYAMA 25MM 52°, 25MM 65°, AND 26MM 85°
- BRESSER 4 Inch f 4.5 AR 102XS Refractor visual observers’ REVIEW
- New Moon Telescopes 16”f/4
- The Ages of Astrophotography 1839-2015
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- Review: Explore Scientific 16”, Europe edition, late 2016
CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.
Dec 09 2014 03:16 PM | Mike I. Jones in Technical Reports
Telescopes are typically stored and operated over a wide range of temperatures. Changing temperatures and extreme temperature ranges affect nearly all materials used in constructing telescopes, as well as the optical properties of the air in the immediate vicinity. This article discusses the two principle effects of temperature on telescope materials: (1) changes in optical and structural material dimensions with temperature, and (2) changes in optical glass refractive index with temperature. These two temperature-dependent material properties usually combine to negatively affect optical performance in refractive and catadioptric systems if not compensated for, and system optimization must account for these properties in the design phase to minimize temperature effects on telescope performance.
Nov 22 2014 02:37 PM | Scott in NC in Other Reports
A. Jaegers Optical Corporation--A personal recollection Stephen L. Nightingale For many teenagers in the 1960’s, an after-school or summer job meant...MacDonald’s! As a teenage amateur astronomer and telescope nut, I had the perfect job--working for Al Jaegers at A. Jaegers Optical Corporation from 1968 to 1970.
Mar 29 2011 05:24 AM | David Knisely in Accessories Reports
I had purchased a QuickFinder to put on the front of the dewcap of my 100mm f/6 refractor, as I was occasionally having trouble getting to the new "correct-image" right angle optical finder I had installed earlier
Jan 12 2011 10:58 AM | David Knisely in New CN Reports in [!monthname!]
The Orion SkyQuest XX14i Truss-tube Dobsonian is a fairly nice large aperture instrument for the amateur who needs something a bit bigger than what is usually offered by the solid tubed telescopes.