June 2005
Beginner
412 pages
13h 45m
English
Content preview from Astronomy HacksBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Tune Your Newtonian Reflector for Maximum Performance
Align your optics to provide the best possible image quality.
Collimation is the process of aligning all mirrors and lenses in a telescope so that they share a common optical axis. Awell-collimated scope provides the best images its mirror or objective lens is capable of providing. A poorly collimated scope has significantly degraded image quality—how degraded it is depends upon how poor the collimation is.
To understand how important proper collimation is, consider two telescopes of the same aperture and focal ratio. One scope has a typical mass-market Chinese mirror, accurate to perhaps 1/4 wavelength or about 0.80 Strehl. (Strehl ratio is a statistical measure of overall mirror quality based on interferometry testing; a perfect mirror—impossible in the real world—has a Strehl ratio of 1.0.) The second scope has a premium mirror, made by a master optician such as Carl Zambuto or R. F. Royce. That premium mirror may cost 5 or 10 times as much as the mass-market mirror, and it is accurate to perhaps 1/20 or 1/40 wavelength, say 0.98 Strehl. There is no comparison between these mirrors. The first is mediocre. The second is world-class.
So we set up the two scopes and point them at Jupiter or Saturn. The inexpensive scope is perfectly collimated. The premium scope is just slightly out of collimation. How do the images compare? The cheap mirror beats the premium mirror, and not just by a little bit. The cheap mirror wins hands-down. ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.