2″ 90-deg 99% Diagonal (SCT)


SKU: ASC439TA Category:

ASC’s 2″ SCT diagonal features dielectric coatings with 99% reflectivity across the visible spectrum and a 1/12 wave BK7 mirror. The all metal diagonal body is CNC machined. The combined result is a superb diagonal offering excellent mechanical and optical quality at a great price.

Out of stock

Guaranteed Safe Checkout

ASC’s 2″ SCTmirror diagonal is an excellent alternative to higher priced diagonals for those on a budget or just getting started in the 2″ format.  This diagonal features Al + SiO2 coatings with 92% reflectivity across the visible spectrum and a 1/10 wave mirror. This ASC diagonal offers excellent mechanical and optical quality at a great price.

You can attach this diagonal directly to Schmidt-Cassegrain telescopes and many Maksutov-Cassegrain telescopes, as long as there is a SCT male thread on the telescope. The standard SCT thread is a 2″x24tpi thread.

A 1.25″-2″ adapter is included so you can use this diagonal with 1.25″ or 2″ eyepieces. The 1.25″ and 2″ holders both feature a brass compression ring, so your eyepiece barrels will not be scratched by the set screw. The 1.25″-2″ adapter is also threaded to accept 2″ filters. The clear aperture is 38.2mm.

Weight0.8 kg
Dimensions10.5 × 12.5 × 17.5 cm


There are no reviews yet.

Only logged in customers who have purchased this product may leave a review.

  • Premium 2″ diagonal with durable dielectric coatings for long lifetime
  • 99% reflectivity across visible spectrum and 1/12-wave BK7 mirror for bright and true images
  • All-metal body with SCT barrel
  • Comes with 2″-1.25″ eyepiece adapter for maximum flexibility
  • Includes foam-fitted storage box and end caps
Shopping Cart
Astronomical Solutions Company

Add address

Scroll to Top

Having difficulty making your purchase? Don’t worry! fill Out the form below, and a real, friendly human being (No bots, we promise!) will swoop in to save the day. 🦸‍♂️🦸‍♀️

Or alternatively send a WhatsApp message to +968 7151 4492 and We will get back to you during working hours!


Let's have a chat