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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Baader BBHS Prism Adjustable Star Diagonal - 2"
Baader BBHS Prism Adjustable Star Diagonal - 2"
Baader BBHS Prism Adjustable Star Diagonal - 2"
Baader BBHS Prism Adjustable Star Diagonal - 2"
Baader BBHS Prism Adjustable Star Diagonal - 2"
Baader BBHS Prism Adjustable Star Diagonal - 2"

Baader BBHS Prism Adjustable Star Diagonal - 2"

by Baader Planetarium
SKU BAA-2456118
$559.00 - $559.00
$559.00
$559.00 - $559.00
$559.00
Price Match Policy!
  • Broad Band Hard Silver (BBHS®) Coated Prism
  • 2-inch ClickLock® Self-Centering Eyepiece Clamp
  • Fully User-Collimatable Prism Mount
  • CNC-Machined Aluminum Housing
  • Integrated 2-inch Filter Threads in Nosepiece
1 in stock
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Baader BBHS Prism Adjustable Star Diagonal - 2"

    The Baader BBHS Prism Adjustable Star Diagonal combines a fully collimatable prism with a 2-inch ClickLock clamp, creating a reference-standard optical link for planetary and visual observation. The prism's Broad Band Hard Silver (BBHS®) coating produces higher contrast and more saturated color compared to standard prisms, mounted in a CNC-machined housing for rapid thermal stability and image stability.

    BBHS® Silver Coating: Broad-Spectrum Reflectivity and Enhanced Contrast

    Unlike diagonals with simpler prism or dielectric coatings, this Baader diagonal uses a Broad Band Hard Silver (BBHS®) coating. This proprietary, multi-layer silver coating is sealed against corrosion and provides exceptionally high reflectivity across a very wide spectral range. The result is a noticeable increase in image brightness, contrast, and color saturation, particularly when observing planets at high magnification through apochromatic refractors.

    The BBHS® process produces no stray light, contributing to a darker background sky and enhanced contrast. In addition to the sealed silver rear surface, the prism also features Baader's Phantom Coating® Group anti-reflection treatment on its optical surfaces to maximize light transmission.

    2-inch ClickLock® Clamp: Secure, Self-Centering Eyepiece Grip

    The integrated 2-inch ClickLock eyepiece clamp secures even the heaviest accessories with a gentle twist of the outer ring. This mechanism uses leverage to apply strong, even pressure from three sides, similar to a machinist's chuck. This three-point grip prevents any tilting and automatically centers the eyepiece barrel perfectly on the optical axis every time.

    This system eliminates the risk of marring your eyepiece barrels with thumbscrews and provides absolute security for heavy eyepieces, binoviewers, or imaging cameras. The modular design also allows for a 2-inch filter to be threaded into the nosepiece for permanent installation.

    Collimatable Prism Mount for Perfect Optical Alignment

    For the most demanding applications, the prism itself is mounted on an adjustable cradle within the CNC-machined aluminum housing. While the diagonal is precisely aligned at the factory, this feature allows an advanced user to make micro-adjustments to achieve perfect collimation with their telescope's optical axis. This is especially valuable for correcting tilt in an imaging train or for building custom binocular telescopes.

    The factory alignment ensures the optical and mechanical axes are perfectly matched. Adjusting the collimation should only be done after eliminating all other potential sources of error, such as focuser tilt. Please note that user adjustment of the collimation voids the warranty on the factory alignment, though all other warranty coverage remains.

    BBHS® Prism vs. Dielectric Mirror: When to Choose This Diagonal

    Choosing between a prism and a mirror diagonal depends on your telescope's focal ratio. Prisms, like this BBHS® model, are generally recommended for telescopes with slower focal ratios (typically f/7 and longer). In these systems, a high-quality prism can deliver superior contrast and color fidelity for planetary and lunar observing compared to a mirror.

    For faster optical systems (f/6 and below), a dielectric mirror diagonal is often preferred to maintain image sharpness. The BBHS® silver prism, however, offers a wider reflective bandwidth than most dielectric mirrors, maintaining high reflectivity into the near-infrared, which can be an advantage for specific imaging applications.

  • What makes the Baader BBHS® prism diagonal different from a standard prism diagonal?

    The Baader BBHS® Prism Diagonal uses a proprietary Broad Band Hard Silver (BBHS®) coating that is sealed for longevity. This provides higher reflectivity across a wider spectrum of light compared to simpler prisms, resulting in visibly brighter images, enhanced contrast, and richer color saturation, especially on planets.

    When should I choose the Baader BBHS® Prism Diagonal over a dielectric mirror diagonal?

    A prism diagonal like the Baader BBHS® is generally the superior choice for telescopes with slower focal ratios (f/7 or longer), such as Schmidt-Cassegrains, Maksutov-Cassegrains, and many refractors. In these instruments, it often provides better contrast and color fidelity than a mirror. For faster telescopes (f/6 or less), a high-quality mirror diagonal is typically recommended.

    How does the 2-inch ClickLock clamp on the Baader BBHS® diagonal work?

    The ClickLock clamp uses a simple, gentle twist of the rubberized ring to operate. Internally, this action engages a three-point clamping system that grips the eyepiece barrel firmly and evenly. This design prevents tilting, automatically centers the accessory on the optical axis, and avoids marring barrels with thumbscrews.

    Can I collimate the Baader BBHS® Prism Diagonal myself?

    Yes, the prism is mounted in an adjustable cradle, allowing for fine collimation. This is an advanced feature for users looking to eliminate every source of tilt in their optical train. However, the diagonal is precision-aligned at the factory. Please be aware that user adjustment of the collimation will void the factory warranty on that alignment.

    How will the Baader BBHS® Prism Diagonal improve views of Jupiter through my 8" f/10 SCT?

    An 8" f/10 SCT is an ideal instrument for the Baader BBHS® Prism Diagonal. You can expect to see a distinct improvement in the color saturation of Jupiter's cloud bands—the Great Red Spot (GRS) and tan belts will appear richer. The complete absence of stray light from the BBHS® coating also enhances contrast, making fine details and smaller storms easier to resolve.

    Can I use 2" filters with the Baader BBHS® Prism Diagonal on my refractor?

    Yes. The 2-inch nosepiece of the Baader BBHS® Prism Diagonal is threaded to accept standard 2-inch astronomy filters. This allows you to install a filter, such as a nebula or light pollution filter, directly into the diagonal for visual observing or imaging sessions with your refractor.

  • Net weight (kg) 0.63
    Deflection angle 90°
    AR-Coating Phantom Coating® Group
    Clamping System ClickLock
    Inner Diameter / Clear Aperture (mm) 47
    Optical length (mm) 100
    Inner Connection (eyepiece/-camera-sided) ø 2" (50.8mm), M55
    Inner Connection (lens sided) M48, 2"/SCT Thread (50.8mm), M55
    Outer Connection (lens sided) ø 2" (50.8mm), S58
    Optical Design Star Diagonal Prism
    Image Orientation Erect image, Mirror inverted
    Reflection surface Sealed BBHS coating
    Glas path 50 mm
  • Baader Planetarium Warranty