Clear aperture ---------
Central obscuration ---
Optical quality --------
Primary and secondary
mirror coatings --------
Field corrector
lens coatings ----------
F/4.9 field corrector ---
F/9 field corrector -----
OTA length ------------
OTA width -------------
OTA weight ------------
Carbon tube -----------
300 mm
165 mm or 55%
Diffraction limited
Broadband high-reflectivity
enhanced aluminum
Broadband multi-layer
anti-reflection coatings
on all surfaces
70 mm diameter three
lens system
70 mm diameter three
lens system
516 mm (20.33")
414 mm (16.3")
50 lbs - approximately
15.3" diameter
Primary substrate ------
Secondary substrate ---
Back focus at f/4.9 -----
Back focus at f/9 -------
Focal length at f/4.9 ----
Focal length at f/9 ------
Field of view - linear ----
Field of view - angular --
Vignetting*
42 mm image circle ----
Vignetting*
55 mm image circle ----
*assumes no adapter/filter obstruction
Fused Quartz 12.5" diameter
Sital 6" diameter
183 mm (7.2")
300 mm (11.8")
1,470 mm
2,700 mm
55 mm diameter at f/4.9
55 mm diameter at f/9
2 degrees diameter at f/4.9
1.2 degrees diameter at f/9
0% at f/4.9
0% at f/9
13% at f/4.9
5% at f/9
© copyright 1994-2010 Ceravolo Optical Systems