A Guide to Choosing Astronomy Eyepieces for Binoviewers

GSO 1.25" 90-deg 99% Dielectric Mirror Diagonal with Compression Ring

Our Price: $68.00
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In Stock (10+ Available)
Ships by Next Business Day
Our Product ID: ODIA-GS-125D-COMP
Manufacturer SKU: ODIA-GS-125D-COMP
Item Can Ship: Worldwide
GSO 1.25" 90-deg 99% Dielectric Mirror Diagonal with Compression Ring

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  • GSO 1.25" 90-deg 99% Dielectric Mirror Diagonal with Compression Ring
  • GSO 1.25" 90-deg 99% Dielectric Mirror Diagonal with Compression Ring

Quick Overview

  • 1.25" 90-deg diagonal features coated BK7 glass mirror precision ground to 1/10th wave flatness
  • Hard dielectric multi-layer coatings with additional protective layer for >99% reflectivity and long lifetime
  • Anodized aluminum finish
  • Precision-machined body includes compression ring and internal safety stop to prevent long barrels from hitting diagonal mirror
  • Threaded for 1.25” filters
  • Comes in a foam-fitted storage box with two end caps

Product Details

New, improved model - Now with compression ring in eyepiece barrel

GSO's new 1.25" dielectric diagonal continues their tradition of offering superb products at excellent prices. This beautiful1.25" mirror diagonal features a BK7 mirror that is precision ground to a flatness of 1/10th wave (minimum) and features dielectric 6-layer enhanced silver coatings with an over-coat protective layer for a light efficiency of over 99% reflectivity across the entire visual spectrum. The clear aperture is 27.9mm.

The mechanics of this diagonal are also top-notch. The robust aluminum body and attachment barrels are precision CNC machined to strict tolerances from solid stock throughout. The 1.25" nosepiece is threaded to accept standard 1.25" astronomy filters. The 1.25" eyepiece holder features a brass compression ring to protect your eyepieces and accessories. It also includes an internal safety stop to prevent long barrels on some eyepieces and barlows from hitting the diagonal mirror. The diagonal sports a handsome anodized finish.

The combined result is a superb diagonal offering excellent mechanical and optical quality at a great price. Dielectric coatings are more durable than regular or enhanced aluminum coatings, so you will enjoy years of excellent performance from this product.

The diagonal comes in a nice foam-fitted storage box and includes 2 end caps. Weight = 5.9oz.. Made in Taiwan.