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Why and how to make a sub-aperture mask for a refractor | 10 Minute Astronomy
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Amazon.com : Telescope for Adults, 70mm Aperture 500mm Refractor Telescope for Astronomy Beginners, 20X-150X, Fully Multi Coated Optics, Portable Travel Telescope with Pro Tripod, Phone Adapter & Backpack : Electronics
Stops and Apertures
A Better Explanation Of The Aperture Mask Technique - Beginners Forum (No Astrophotography) - Cloudy Nights
Why Aperture is so Important in Astrophotography • PhotographingSpace.com
Why and how to make a sub-aperture mask for a refractor | 10 Minute Astronomy
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