Optical Accessories

The Svbony SV193 combines two essential functions for ambitious astrophotographers: focal length reduction and field flattening. With a reduction factor of 0.8, it shortens the effective focal length of the SV503 80mm f/7 from 560 mm to approximately 448 mm, enabling a wider field of view and shorter exposure times—ideal for deep-sky imaging.

Technical Features

• Optical design: 3 elements in 3 groups, fully multi-coated for high light transmission and minimized reflections
• Connection: 2″ barrel with M54x0.75 thread for cameras; compatible with full-frame sensors
• Filter thread: Standard 2″ thread for integrating light pollution filters
• Housing: Hard-anodized aluminum, lightweight and durable
• Field flattening: Corrects spherical aberration and edge distortion for sharp star images across the entire field

This reducer reduces the focal length of the Askar 111F by a factor of 0.74x and significantly shortens the exposure time in astrophotography

• The reducer was designed for the Askar 111F flat-field apochromat
• The focal length is reduced to 566mm
• The focal ratio is improved from f/6,9to f/5.1
• A triplet design maintains the flat field
• The reducer is screwed directly onto the M68x1 female thread of the apos´ M78-M54 adapter
• The apo´s photo adapters can be used directly
• The working distance from the M48x0.75 thread on the camera side is 55 mm

This reducer reduces the focal length of the Askar 131F by a factor of 0.74x and significantly shortens the exposure time in astrophotography

• The reducer was designed for the Askar 131F flat-field apochromat
• The focal length is reduced to 727 mm
• The focal ratio is improved from f/7.5 to f/5.5
• A triplet design maintains the flat field
• The reducer is screwed directly onto the M72x1 female thread of the apos´ M78-M54 adapter
• The apo´s photo adapters can be used directly
• The working distance from the M48x0.75 thread on the camera side is 55 mm