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Bausch & Lomb Criterion 4000 4-inch (100mm) f/12 Catadioptric/Cassegra - $250 (Lake Panasoffkee)
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Key Specifications & Features
• Optical Design: 4" aperture with a 1200mm focal length (f/12). Some optical discussions note it functions closer to a standard Cassegrain system.
• Build Quality: Features a robust, machined aluminum and stainless steel body rather than the heavy plastic common in later consumer scopes.
• Portability: Weighs roughly 4.5 kg (10 lbs), making it a compact grab-and-go or travel telescope that can attach to standard 1/4"-20 tripod threads.
• Performance: Performs best at lower magnifications (40x–50x) for wide-field scanning or lunar viewing. Optics can be "hit-or-miss", with higher magnifications (>100x) frequently revealing spherical aberration or soft focus.