Hubble Telescope at 10x or 100x or 1000x The other night I caught a new documentary, “Hubble’s Amazing Universe” on the National Geographic Channel that in high definition wonder showed how the Hubble Space Telescope revolutionized astronomy since 1993. telescope focal length / clear aperture = focal ratio For example, a telescope with a focal length of 1000mm and a 100mm (4") clear aperture has a focal ratio of f/10 (1000/100=10). by Richard Berry, 8.50" by 11.00", 240 pages, hardbound, 3rd Editon published 2001, $29.95. An example calculation of focal ratio and magnification for a scope with a 25 mm focal length, eyepiece, 102 mm aperture, and 900 mm focal length, telescope. 99 $129.99 $129.99 How to Make a PVC Telescope: Placing any two convex lenses (with different focal lengths) a distance apart will create an up-side-down magnified image of far away objects.These are instructions on how to make a simple telescope out of everyday parts (PVC pipe / magnifying lense… ABOUT THE BOOK… For anyone who has ever dreamed of exploring the heavens with a telescope, Build Your Own Telescope can make that dream come true. And while this isn't a false claim because the telescope in reference will actually go to that magnification it is a worthless number because telescopes have definite limits to … Gskyer Telescope, 70mm Aperture 400mm AZ Mount Astronomical Refracting Telescope for Kids Beginners - Travel Telescope with Carry Bag, Phone Adapter and Wireless Remote 4.4 out of 5 stars 8,489 $99.99 $ 99 . Large BAK-4 Prism inside and Fully Multi-coated Lens Coating: Strengthen the key function of a monocular, guarantee superior light transmission and brightness, make your view brighter, clearer, and delivers crisp images. Often times you will see telescopes for sale that claim big magnifications such as up to 1000X power or 500X power telescope. ; Waterproof, Dust-proof, and Shockproof Design: Nitrogen-filled waterproof and O-ring sealed optics prevent moisture, dust, and debris and ensures the living waterproof function.