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Tele Vue 90º Everbrite Diagonal 1

Tele Vue 90º Everbrite Diagonal - 2"

by TeleVue
SKU TV-DDP-8004
$450.00 USD - $450.00 USD
$450.00 USD
$450.00 USD - $450.00 USD
$450.00 USD
Price Match Policy!
  • Reflectivity: 99% Dielectric Coatings
  • Mirror Substrate: Pyrex
  • Body Construction: CNC-Machined Aluminum
  • Eyepiece Holder: Non-Marring Brass Clamp Ring
  • Barrel Size: 2-inch with 1.25-inch adapter
  • Filter Threads: Yes (48mm)
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • The Last Diagonal You'll Ever Need: The Tele Vue 90º Everbrite Diagonal

    The Tele Vue 90º Everbrite Diagonal is an essential optical component engineered to transmit the maximum amount of light from your telescope to your eyepiece without degrading the image. For observers who refuse to compromise on brightness, contrast, or mechanical integrity, this 2-inch star diagonal serves as a permanent, reference-grade link in the optical chain, ensuring the view your telescope produces is exactly the view your eye receives.

    Unlike standard aluminum or silver diagonals that can tarnish and lose reflectivity over time, the Everbrite is built for a lifetime of service. It combines a thermally stable Pyrex mirror with a state-of-the-art dielectric coating system, all housed in a solid, single-piece body that guarantees perfect alignment. This isn't just an accessory; it's an investment in the performance of your entire telescope system.

    99% Reflectivity Dielectric Coatings

    The heart of the Everbrite is its mirror, which features a 50-layer dielectric coating system. This advanced coating provides a certified reflectivity of 99% across the entire visual spectrum. The practical benefit is a visibly brighter image with more vibrant color saturation compared to diagonals using standard aluminum coatings, which typically reflect only 88-92% of light.

    This increase in light throughput is most noticeable on faint deep-sky objects. The wispy outer arms of the Triangulum Galaxy (M33) or the faint mottling within the Orion Nebula (M42) gain a subtle but definite boost in contrast and visibility. The coatings are also exceptionally durable, resisting the gradual oxidation that degrades traditional mirror surfaces over years of use.

    The Everbrite Dielectric Coating

    Everbrite is not a separate over-coat: it is the dielectric coating itself, built up from more than 50 layers. Clean the mirror only when absolutely necessary, since dust or abrasive particles wiped across the surface can scratch it.

    Thermally Stable Pyrex Substrate

    A mirror's coating is only as good as the surface it's on. The Everbrite uses a low-expansion Pyrex substrate, which is far more resistant to temperature changes than the plate glass found in budget diagonals. As your telescope cools to ambient temperature during an observing session, the Pyrex mirror maintains its precise 1/10-wave optical figure, preventing the introduction of astigmatism or other aberrations that can soften the view.

    Solid, Single-Piece CNC-Machined Housing

    Many diagonals are assembled from multiple screwed-together parts, creating potential points of flexure or misalignment. The Everbrite body is machined from a single block of solid aluminum to ensure permanent, perfect alignment between the telescope's optical axis and the eyepiece. This rigid, unyielding structure means that even heavy eyepieces or binoviewers will not cause the diagonal to sag or shift, preserving the sharp collimation of your optical system.

    Non-Marring Brass Clamp Ring

    Protecting your eyepiece investment is critical. Instead of a simple set screw that digs into the barrel, the Everbrite uses a soft brass clamp ring. As you tighten the oversized screw, this internal ring compresses gently and evenly around the eyepiece barrel. This mechanism provides a more secure grip across a wider surface area and completely avoids the scratches and gouges that set screws inflict.

    Contrast-Enhancing Baffling

    To deliver the highest possible contrast, a diagonal must control stray light. The interior of the Everbrite is machined with anti-reflection threads and finished in a flat black. This baffling system traps any off-axis light that enters the diagonal, preventing it from reflecting into the eyepiece. The result is a darker background sky, which makes it easier to perceive faint details, like the delicate Cassini Division in Saturn's rings or the faint stars at the core of globular cluster M13.

    Choosing the Right Tele Vue Diagonal

    Tele Vue offers several high-performance diagonals, and the choice depends on your telescope and observing goals. The Everbrite is the definitive choice for refractors and Schmidt-Cassegrains where light-gathering and long-term durability are paramount.

    • vs. Tele Vue 1.25" Everbrite (DPC-1250): The 2-inch Everbrite is the logical upgrade for telescopes with 2-inch focusers. It allows the use of wide-field 2-inch eyepieces and provides a more robust, stable platform. The 1.25-inch model is an excellent choice for smaller telescopes or when weight is a primary concern.
    • With the Tele Vue SCT Adapter (ACC-0003): ACC-0003 is not a diagonal. It threads onto the standard SCT rear cell and holds this 2" Everbrite, the pairing Tele Vue sells as the 2" SCT RichField Kit (SCP-8202).

  • Is a dielectric diagonal better than a prism diagonal?

    For most applications, yes. A high-quality dielectric mirror diagonal like the Everbrite offers higher light transmission and better color accuracy than most prisms. Prisms can sometimes offer slightly higher contrast, but they can also introduce chromatic aberration in short focal ratio telescopes (below f/7).

    Will the Tele Vue Everbrite work with my Schmidt-Cassegrain Telescope (SCT)?

    Yes, the 2-inch Everbrite slides into any standard 2-inch visual back or focuser on an SCT. For a threaded connection, add the Tele Vue SCT Adapter (ACC-0003), which threads onto the rear cell and holds this diagonal.

    Why is the Everbrite more expensive than other dielectric diagonals?

    The cost reflects the combination of a 1/10-wave Pyrex mirror, the Everbrite dielectric coating of more than 50 layers, and the precision CNC-machined single-piece housing. These elements together ensure thermal stability, perfect alignment, and a lifetime of consistent performance that cheaper, multi-part diagonals cannot guarantee.

    Do I need a 2-inch diagonal if I only have 1.25-inch eyepieces?

    Even if you only use 1.25-inch eyepieces now, a 2-inch diagonal is a future-proof investment. It allows you to upgrade to wide-field 2-inch eyepieces later without needing to buy another diagonal. The included 1.25-inch adapter is high quality and maintains perfect centering.

    How often should I clean the Everbrite mirror?

    Almost never. Clean the mirror only when absolutely necessary, and the diagonal should be kept capped when not in use. Cleaning should only be considered after years of use if significant dust has accumulated that cannot be removed with an air bulb.

  • Model # DDP-8004
    Type Mirror Diagonal (Star Diagonal)
    Angle 90-degree
    Barrel Size 2-inch
    Adapter 2"-1.25" HiHat adapter with brass clamp ring (included)
    Mirror 1/10 wave Pyrex substrate
    Coatings Everbrite dielectric, more than 50 layers
    Reflectivity 99% across visual spectrum
    Eyepiece Clamp Brass clamp ring (non-marring)
    Housing One-piece CNC machined aluminum
    Filter Threads Yes, for standard 2-inch (48mm) filters
    Telescope-Side Connection 2" barrel
    • Tele Vue 90º Everbrite 2-inch Diagonal

      Tele Vue 90º Everbrite 2-inch Diagonal

      × 1

    • Tele Vue 2-inch to 1.25-inch Adapter

      2"-1.25" HiHat Adapter with Brass Clamp Ring

      × 1

    • Tele Vue 2-inch Dust Cap

      2" Barrel Dust Cap

      × 1

    • Tele Vue 2-inch Eyepiece Dust Cap

      2" Eyepiece Port Dust Cap

      × 1

  • Tele Vue 5-Year Limited Warranty