Reflectors

Collimating a 400mm f/20 Classic Cassegrain

400mm f/20 Classic Cassegrain on collimation bench

August 30, 2024

Collimating a Classic Cassegrain telescope – or any telescope with more than one curved mirror – is not easy. Catalin from CFF Telescopes collimated this 400mm f/20 with an artificial star, a beam splitter and an optically flat mirror.

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For sale – refurbished QHY600M-Pro camera

December 3, 2025

FOR SALE: QHY600M-Pro Condition: external marking but internally refurbished by QHY. No accessories included. Price $7000 (new price is around $14,000) Contact: Diego on Facebook at https://www.facebook.com/dcolonnello Details This is a…

December 3, 2025

PegasusAstro focus, power and dew heater controllers use a range of temperature and environmental sensors. Knowing which one goes with what product can be confusing. Bill’s written a handy list for you.

November 14, 2025

Every month, I present a talk at the Astronomical Society of Victoria on what’s up in the sky. They’re uploaded to YouTube and a few other video sites, and I…

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Reflectors

Collimating a 400mm f/20 Classic Cassegrain

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