The SVBONY SV222 1.25″ 90-degree Erect Prism Diagonal is designed to provide a correctly oriented, upright image for both terrestrial and astronomical observing. Using an erecting prism rather than a mirror, it delivers a true daytime orientation while maintaining good contrast and brightness for refractor telescopes.

Key Features

• Upright, Correct-Image Viewing
  Erecting prism design produces a right-side-up, non-reversed image, ideal for terrestrial observing and daytime use.
• Fully Multi-Coated Prism Optics
  Anti-reflection coatings reduce glare and scattering, improving contrast and overall image clarity.
• Precision All-Metal Construction
  CNC-machined aluminium body with black anodised finish ensures durability and long-term mechanical stability.
• Internal Light Control
  Blackened, baffled interior and threaded light path minimise stray light and improve image definition.
• Secure 1.25″ Eyepiece Clamping
  Brass pressure ring and locking system hold eyepieces firmly while protecting barrels from damage.

Erect Prism for Correct Orientation

Unlike standard mirror diagonals, the SV222 prism diagonal provides a face-up, non-inverted image. This makes it particularly suitable for terrestrial viewing, wildlife observation, and daytime landscape use with refractors.

Optical Coatings & Contrast Control

Fully multi-coated prism surfaces reduce internal reflections and light loss, delivering brighter images with improved contrast compared to uncoated prisms.

Internal Matting & Threaded Design

Matte-black internal surfaces and threaded light paths absorb stray light, helping to maintain image clarity and reduce glare during observation.

Brass Compression Ring & Safety Features

The brass pressure ring secures eyepieces evenly without scratching. An internal safety stop prevents eyepiece barrels from contacting the prism surface.

Filter Compatibility

Standard 1.25″ filter threads allow easy attachment of astronomical filters, extending versatility for different observing conditions.

Typical Use Cases

• Terrestrial and daytime observing with refractors
• Correctly oriented lunar and planetary viewing
• Wildlife and landscape observation
• Users requiring true image orientation

Key Specifications

• Diagonal size: 1.25″
• Angle: 90°
• Optical type: Erecting prism
• Coatings: Fully multi-coated, anti-reflection
• Eyepiece clamp: Brass compression ring
• Filter thread: 1.25″

Compatibility Notes

• Designed for refractor telescopes
• Produces correct-image orientation
• Not intended for fast focal-ratio astro-imaging systems