- Comparison of the Boltwood II and Sky Alert Cloud Sensors
- Chile Dilly!
- 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
- Stardust Gallery LED Lightbox and Metallic Print Review
- Rayox Saddle Review
- MoonLite NiteCrawler Focuser
- Celestron Cometron 7x50s Review
- Astro-Devices (of Ukraine) Parallelogram Standard II Pro
- Review: Explore Scientific 16”, Europe edition, late 2016
- VITE 2X Barlow Lens Review
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.
Oct 14 2005 03:32 PM | CN_Admin in Technical Reports
Today there seem to be more amateurs than ever getting into the hobby, and like many of us, they are not just interested in the targets in the night sky but the optical systems themselves. Although seemingly simple an optical system is quite a complex thing, with various and confusing elements.
Mar 22 2005 11:41 AM | admin in Technical Reports
In a telescope, you can vary the exit pupil by changing the eyepiece. In a fixed power binocular the exit pupil you purchase is the exit pupil you live with. The question answered here is this: What happens when your eye pupil is smaller than the binocular exit pupil
Mar 22 2005 11:32 AM | admin in Technical Reports
Ever hear of mirror flexing? If not, you are in for a treat with this article. Carlos takes you step by step through a complete newtonian conversion project