Clear aperture – 250 mm
Focal ratio – 15; Focal length – 3750 mm
Central Obstruction – 26%
Focal ratio – 20; Focal length – 5000 mm
Central Obstruction – 24%
Primary substrate – Supremax33; Zerodur or Clearceram HS (special order)
Secondary substrate – Quartz
Manual adjustments/collimation for both mirrors
Primary cooling fans
Primary mirror cage – Carbon Fiber
Truss tubes – Carbon Fiber
Dimensions:
(approx.) 930 x 330 x 330 mm (including focuser’s height)
Weight – 13 kg
Back-focus from end of back plate – ~230 mm
Focuser: 2′ Feathertouch R&P or 2′ Moonlite DC
Focuser travel: 38 mm
Items included:
– shroud pack (secondary casing shroud, secondary cage shroud, truss shroud)
– side plates (pair);
– handle;
– 350 mm D-type dovetail
Reviews
CFF 250 F/20 CC – Goncalo Carvalho, Lisboa, Portugal
“What I can tell you is that this telescope gives wonderful contrasty views of the planets and globulars, better than my ex 180 mm APO refractor, and with a neutral color image. The focus is not archived by moving mirrors and the thermal stability of the OTA is surprisingly good, I don´t see any change in focus over time or with temperature change!!’
