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Svbony SV223 1.25" 90° Clicklock Dielectric Diagonal Mirror
The Svbony SV223 1.25" 90° Clicklock Dielectric Diagonal Mirror combines a lab-tested dielectric mirror with >99% reflectivity and a secure Clicklock clamping system. This design directs the maximum amount of light from your telescope to your eyepiece through its 25mm clear aperture, providing brighter, higher-contrast views than standard diagonals. The robust metal body adds only 249g to your optical train while ensuring your eyepieces are held with absolute stability.
The SV223's >99% Reflectivity Dielectric Mirror
At the core of the SV223 is a precision 11.5mm thick optical flat mirror with a multi-layer dielectric coating. This advanced coating achieves over 99% reflectivity across the visual spectrum, preventing the light loss common in standard aluminum or silver-coated diagonals. The result is a tangible increase in image brightness and contrast, allowing you to resolve finer details on planets and detect fainter stars in clusters.
Instant Security: The 1.25" Clicklock Clamping System
Fumbling with small thumbscrews in the dark is eliminated with the SV223's Clicklock mechanism. A simple twist of the outer ring tightens a stainless steel compression ring, securely centering and locking your 1.25" eyepiece or accessory in place without marring the barrel. This system provides a solid, repeatable connection that maintains perfect alignment, critical for high-magnification planetary viewing or imaging.
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Fast Clamping Action: Lock or release any 1.25" accessory in seconds with a gentle twist, even while wearing gloves.
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Damage-Free Design: The internal compression ring grips the eyepiece barrel evenly, avoiding the scratches and dents caused by single thumbscrews.
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Baffled Interior: The metal housing is internally baffled and blackened to absorb stray light, further enhancing image contrast by preventing internal reflections.
SV223 Dielectric vs. Standard Diagonals: A Clear Upgrade
Compared to a standard prism or aluminum-coated mirror diagonal, the SV223 offers a significant step up in optical and mechanical stability. While a standard diagonal might reflect 88-92% of light, the SV223's >99% dielectric coating delivers a noticeably brighter image at the eyepiece.
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Standard Aluminum Mirror: Typically has lower reflectivity and is prone to degradation over time, reducing brightness and contrast. The SV223's dielectric coating is far more durable and maintains its reflectivity for years.
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Prism Diagonal: Can introduce chromatic aberration in fast telescopes (below f/7), whereas the SV223 mirror is color-neutral at any focal ratio.
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Thumbscrew Clamp: A single thumbscrew can cause eyepiece tilt and damage barrels. The SV223's Clicklock ensures perfect centering and a secure, damage-free grip every time.
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What is the main advantage of the SV223's Clicklock system?
The primary advantage of the Clicklock clamping system is its ability to securely and perfectly center any 1.25" eyepiece with a simple twist. This eliminates the risk of eyepiece tilt that can occur with single-thumbscrew diagonals and prevents scratches or dents on your eyepiece barrels.
How will the SV223's >99% reflectivity affect views of Jupiter in my 8" SCT?
In an 8" SCT, the SV223's >99% reflectivity provides a visibly brighter image of Jupiter compared to a standard diagonal with ~90% reflectivity. This increased light throughput enhances the contrast of subtle features like the Great Red Spot (GRS) and delicate cloud bands, making them easier to resolve at high magnification.
Is a dielectric mirror like the one in the SV223 better than a prism diagonal?
For most telescopes, especially "fast" refractors or Newtonians (f/7 or lower), a dielectric mirror diagonal like the SV223 is superior. It introduces zero chromatic aberration (false color), unlike a prism which can create color fringing on bright objects in fast optical systems. The SV223's mirror design ensures color-pure images regardless of your telescope's focal ratio.
Can I use 1.25" filters with the Svbony SV223 diagonal?
Yes. The 1.25" nosepiece of the SV223 diagonal has standard M28.5x0.6 threads, allowing you to attach any 1.25" astronomical filter, such as a moon filter, light pollution filter, or planetary color filters.
What is the optical length of the SV223 and why does it matter?
The SV223 has an optical length of approximately 85.5mm. This is the amount of light path it adds to your telescope's focal plane. This is a standard length for 1.25" diagonals and should allow most refractors and SCTs to reach focus without issue. However, for some Newtonians not designed for visual use, you may need to check your focuser's travel range.
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| Brand |
SVBONY |
| Model |
SV223 |
| Size |
1.25" |
| Deflection Angle |
90° |
| Optical Design |
Mirror Diagonal |
| Reflectivity |
>99% |
| Reflection Surface |
Dielectrically Coated |
| Clear Aperture |
25mm |
| Clamping System |
Clicklock |
| Filter Threads (Lens Side) |
M28.5x0.6 |
| Eyepiece Connection |
1.25" Clamp |
| Telescope Connection |
1.25" Barrel |
| Image Orientation |
Erect image, Mirror Inverted |
| Optical Length |
approx. 85.5mm |
| Mirror Thickness |
11.5mm |
| Material |
Metal |
| Net Weight |
249g / 8.78oz |
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SV223 1.25" 90° Clicklock Dielectric Diagonal Mirror
× 1
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Dust Cap (Eyepiece Side)
× 1
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Dust Plug (Barrel Side)
× 1
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This accessory does not require software or a dedicated manual for operation.
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SVBONY 1-Year Warranty
