Ceravolo 300 Astrograph Specifications

Clear aperture ----- 300 mm

Central obscuration ----- 165 mm or 55%

Optical quality ----- Diffraction limited

Primary and secondary mirror coatings ----- Enhanced aluminum

Field corrector lens coatings ----- Multi-layer anti-reflection coatings on all surfaces

F/4.9 field corrector ----- 70 mm diameter three lens system

F/9 field corrector ----- 70 mm diameter three lens system

OTA length ----- 516 mm (20.33")

OTA width ----- 414 mm (16.3")

OTA weight ----- 50 lbs - approximately

Carbon tube ----- 15.3" diameter

Primary substrate ----- Fused Quartz 12.5" diameter

Secondary substrate ----- Sital 6" diameter

Back focus at f/4.9 ----- 183 mm (7.2")

Back focus at f/9 ----- 300 mm (11.8")

Focal length at f/4.9 ---- 1,470 mm

Focal length at f/9 ----- 2,700 mm

Field of view - linear ----- 55 mm diameter at f/4.9 ----- 55 mm diameter at f/9

Field of view - angular ----- 2 degrees diameter at f/4.9 ----- 1.2 degrees diameter at f/9


Vignetting* 42 mm image circle ---- 0% at f/4.9 ----- 0% at f/9

Vignetting* 55 mm image circle ----- 13% at f/4.9 ----- 5% at f/9


*assumes no adapter/filter obstruction