Manufacturers & Suppliers of Astronomical Telescopes in India Serving Amateur Astronomers Since 1976

EYEPIECES & ACCESSORIES
GSO 1.25" Dielectric Mirror Diagonal CNC
GSO : INDIA
₹ 4800 + 18% GST Arriving Soon Pre Book Now Pay ₹ 4800 to Pre Book

GSO’s latest 1.25" dielectric diagonal upholds their reputation for delivering high-quality optics at great value. This elegant diagonal features a precision-polished BK7 mirror with a flatness of at least 1/10th wave. It’s coated with six layers of enhanced dielectric silver, topped with a protective overcoat, delivering over 99% reflectivity across the visible spectrum. The clear aperture measures 27.9mm.

Crafted with precision, the diagonal boasts a solid aluminum body and attachment barrels that are CNC-machined from solid stock to tight tolerances. The 1.25" nosepiece is threaded to accommodate standard astronomy filters, while the eyepiece holder includes a brass compression ring to securely hold accessories without marring them. An internal safety stop is built in to protect the mirror from long-barreled eyepieces or barlows. The unit is finished with a sleek anodized coating.

The result is an outstanding diagonal that combines superior optical and mechanical quality at an affordable price. Thanks to the durable dielectric coatings, this diagonal is built to provide long-lasting performance.

It comes packaged in a foam-lined storage box with two protective end caps. The eyepiece insertion depth is 30mm (1.18"), and it weighs 5.9 oz. While GSO hasn't officially listed the optical path length, measurements suggest it is approximately 80mm. Made in Taiwan.

  • 1.25" 90° star diagonal with precision-ground BK7 glass mirror

  • Mirror flatness: 1/10th wave minimum

  • Dielectric multi-layer coatings with protective overcoat

  • Reflectivity: >99% across the visible spectrum

  • Clear aperture: 27.9mm

  • CNC-machined aluminum body with anodized finish

  • 1.25" nosepiece threaded to accept standard astronomy filters

  • Eyepiece holder with brass compression ring for secure, scratch-free grip

  • Internal safety stop to prevent long eyepiece/barlow barrels from contacting the mirror

  • Eyepiece insertion depth: 30mm (1.18")

  • Weight: 5.9 oz (approx. 167g)

  • Optical path length: ~80mm (measured)

  • Includes foam-fitted storage box and two dust caps

  • Made in Taiwan

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