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Would you be interested in a true 3248 mm f/8? https://www.telescope.com/Astrophotography/Astrophotography-Telescopes/Orion-16-f8-Truss-Tube-Ritchey-Chretien-A

by mgdlbp 4y ago

Would you be interested in a true 3248 mm f/8? https://www.telescope.com/Astrophotography/Astrophotography-Telescopes/Orion-16-f8-Truss-Tube-Ritchey-Chretien-Astrograph/pc/-1/c/4/sc/19/p/137265.uts https://www.telescope.com/Astrophotography/Astrophotography-... Telescopes do tend to prefer specifying girth rather than length, though.

dekhn 4y ago
I've used a refractor (4" lens, f7, 714mm focal length) as a telephoto. It's great. I ended up buying a crazy-ass lens and building a solar telescope (look at the sun) which was fun until the focal point melted the enclosure.