How Fast is Your Telescope?
Aperture, f-ratios, myths, etc. | Ask Craig | Stark Labs
Telescopes for Astrophotography
ZipDob - the Zip Dobsonian - Mel Bartels
Focal length in detail - Beginners Forum (No astrophotography) - Cloudy Nights
astronomical optics, part 2: telescope & eyepiece combined
Laser Beam Expanders | Edmund Optics
Telescope Astronomy Physics - Notes
Focal Ratio vs. Aperture: What Makes an Object Look Brighter Through a Telescope? - Sky & Telescope - Sky & Telescope
Please explain focal ratio vs. exposure time - Beginning Deep Sky Imaging - Cloudy Nights
focal ratio – Society for Popular Astronomy
f-ratio myth
Lecture 3
What is Focal Length – Distance Light Travels in Telescopes
Optical system of a telescope
Tele Vue Optics: Imaging Methods
Simple Formulas for the Telescope Owner - Sky & Telescope - Sky & Telescope
Lecture 7: Optics and Telescopes
f-number - Wikipedia
Optics for Astronomy
Schmidt-Cassegrains — Starizona
How to Choose Eyepieces for Your Astronomy Telescope
