Model | SV223 | SV223 | SV222 | SV222 | SV221 | SV221 | SV188/P | SV188/P | SV138 | |
SKU | W9180A | W9180B | W9179A | W9179B | W9178A | W9178B | F9171A | F9171B | W9107A | W2733A |
Deflection Angle | 90° | 90° | 45° | 90° | 90° | 45° | 90° | 90° | 45° | 90° |
Diameter | 1.25inch | 2inch | 1.25inch | 1.25inch | 1.25inch | 1.25inch | 1.25inch | 1.25inch | 1.25inch | 2inch |
Type | Mirror | Mirror | Prism | Prism | Mirror | Prism | Mirror | Mirror | Prism | Mirror |
left and right imaging | reverse | reverse | forward | forward | reverse | forward | reverse | reverse | forward | reverse |
Up and down imaging | forward | forward | forward | forward | forward | forward | forward | forward | forward | forward |
Equivalent optical path (mm) | 85.5 | 109.1/118.6 | 93 | 65.6 | 73 | 86 | 78.5 | 78.5 | ||
Effective aperture | 25mm | 43mm | 16mm | 19mm | 29.5mm | 19mm | 27mm | |||
Advantage | Coaxial locking, high-reflective dielectric coating, high surface accuracy | Coaxial locking, high reflective dielectric coating, high surface accuracy, dozens of layers of coating, high surface accuracy | Suitable for astronomical observations | Suitable for astronomical observations | Suitable for astronomical observations | Suitable for astronomical observations | Highly reflective dielectric coating |