1. Final Announcement: We're Saying Goodbye to AstronomyConnect. Read Our Closing Notice.
Dismiss Notice
New Cookie Policy
On May 24, 2018, we published revised versions of our Terms and Rules and Cookie Policy. Your use of AstronomyConnect.com’s services is subject to these revised terms.

More Views

William Optics 2" Quartz Dielectric Coating Diagonal for Refractors

5.0 (1 Reviews) Read Reviews Write Review
Brand William Optics
Part Number D-DIG2QD

Product Info

Manufacturer Description

If what you are looking for is the highest achievable brightness, contrast and sharpness during critical observations with high-end instruments, WO 90° 2" mirror Quartz Dielectric star Diagonal is your choice. We recommend this product for everyone who only wants the best.

Top-Notch Performance and Brightness
• Dielectric coating allows 99% reflectivity.
• 10mm thick substrate flat for optimal image stability
• Quartz being a harder material, it can be polished to a higher accuracy. Quartz also boasts one of the lowest expansion rate compared to other materials.
• Accurate design guarantees constant alignment. No further alignment needed.

Meticulous Craftsmanship
• 2" to 1.25" eyepiece adapter included.
• Lock screw for eyepiece/adapter.
• Big, knurled thumbscrews easy to turn even with gloves on.

Strikingly Beautiful
• Patented, elegant design.
• High-quality machining out of the best aluminum.
• Internally antireflection threaded for highest contrast.

Superbly Constructed
• Compression rings (both on diagonal and adapter) to prevent barrels-marring.
• Internal safety stop prevents 2" barrels from hitting the mirror.

Why W.O. diagonals do not feature an Adjustable alignment system?
Having an adjustable alignment system is an admission that the diagonal can go out of collimation due to poor mechanical construction. Thanks to the patented design of WO diagonals, you will always have a diagonal that performs perfectly like the first day you got one!

• Ultra High Dielectric 99% reflectivity
• Highest precision surface with 10mm-thick mirror.
• 2"- 1.25" adapter with brass clamping ring.
• Inside diameter (48mm): threaded to fit a variety of filters.
• Weight: 470 g


5.0 (Based on 1 Reviews) 100% of reviewers recommended this product.
Rating Distribution
Sort by
  • Date
  • Rating
  • Useful
    1. Guest

      Skill Level
      Time with Product
      User Notes:
      Review by CPCMark of Carlsbad, CA.
      Jan 11, 2011

      5.0 The best!


      Strong Construction,Accurate,Excellent fit and finish




      The build quality of this diagonal is extremely high. The fit, finish and quality of the mirror are all first-rate. Typical of William Optics quality, the diagonal was securely packed, had excellent finish and the optical performance was better than expected. A nice surprise was that the unit I received was the carbon fiber model, not the one pictured! The price is high compared to other diagonals, but if you want the best, this is it!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    Sort by
    • Date
    • Rating
    • Useful