TeleVue Everbrite SC 90° 2″ – Diagonal Mirror

TeleVue Everbrite SC 90° 2″: Diagonal mirror: 2 inch diagonal with SC threaded screw

The Everbrite SC screws directly onto the rear of a Schmidt-Cassegrain without a visual back or intermediate pieces. This eliminates a clamping connection in the light path and keeps the optical axis tight.

The mirror itself is the well-known Everbrite: 99 percent reflectivity, dielectric coating and a 2-inch eyepiece with reduction.

Why the dielectric coating matters

Every star diagonal sits right in the middle of the light path; what the coating does not reflect is lost. The Everbrite mirrors reflect 99 percent across the entire visible spectrum, with a mirror surface polished flat to within one-tenth of a wavelength.

Furthermore, the dielectric coating is hard and wear-resistant: no protective layer that ages, but a surface that lasts for decades and can simply be cleaned.

Direct on the SC wire

The fixed screw connection is stiffer than a clamp ring and repeatable: the diagonal returns to exactly the same position every time. This prevents bending and warping of the collimation when using heavy 2-inch eyepieces.

However, check the backfocus of your configuration; a 2-inch diagonal uses more light than a 1.25-inch one. On common SCs of 200 mm and larger, that space is there.

Featured accessories

The diagonal combines with every eyepiece from the TeleVue lineup; the compression ring also securely holds heavy 2-inch eyepieces. A nebula filter can be screwed directly into the nose of the mirror.

For whom yes and for whom no

• ✓ Schmidt-Cassegrains with standard SC rear thread
• ✓ Owners of heavy 2-inch eyepieces
• ✓ Who wants clamp connections from the light path
• ✗ Refractors, choose the regular 2 inch Everbrite for that
• ✗ Small Maksutovs without SC thread

Specifications

You can find the complete product line for this brand at the TeleVue brand page.