The Celestron C90 Maksutov Cassegrain Telescope
Yesterday, 11:00 PM by skyaddict
William Optics Zenithstar 71ED and Twilight I M...
Feb 28 2015 04:53 PM by Ahab
If you want to Master your craft, read Lessons...
Jan 07 2015 05:29 PM by AstroDad
Celestron Ultima 80
Dec 16 2014 11:54 PM by Gianluca67
Categories See All →
- CN Reports
- User Reviews
- How to . . .
- Observing Skills
- Astronomical History
- Optical Theory
- Vision and Related Experiments
- How to Gain the Support of your Family for your Astronomical Pursuits
- Evaluation Tips
- Special Events
- The Elements
- New Articles in [!monthname!]
- Telescope Articles
- Submit a Review / Article
- Monthly Guides
- Behind the Scenes
- About Us
- Copyright ©
- Terms & Conditions
- Tiny Eyes on the Skies
- From the Editor's Desk
- What's Up . . .
- The Light Cup Journals
- Who is this Super Light Cup?
- Cloudy Nights T-Shirts
- Imaging Contest
- Small Wonders
- Previous Imaging Contest Winners
- This Month's Skies
- Mike's Corner
- The Cloudy Nights Friends and Family Discount
- Uncle Rod's Astro Blog
- Fishing for Photons
- Binocular Universe
- Article Submissions
Technical Reports Archives
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.
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.
An excellent and detailed article on how to build your own Pier.
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
Take a laser, 2 professional scientists and a large box of eyepieces and what do you get? Some really interesting data on the amount of light transmission through the eyepieces
Are you a new newt owner? John Crilly gives us this beginners rundown on newtonian collimation....
Albert Bellg critiques both his own review of the TMB monos and a recent Sky & Tel review. Did some errors occur?
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
Want to make your own lost cost artificial star? This article will lay out the steps for doing so.
Ever wonder how you disassemble and clean an achromat refractor? This article lays out the steps in a clear to understand manner.
Optical designer Thomas Back explains what spherical aberration is and why you need to know about it
Diffraction and The Airy Disk, Dawes Limit & Rayleigh Criterion
What does it look like when you put a Meade 2045 SCT through a CT-Scan? The results are fascinating
What exactly is the limiting magnitude of a pair of binoculars? Does it depend on the size? The magnification?
Do you really understand binocular performance? If you don't now, you will when you finish this review