Ritchey-Chrétien 250mm F/8
Clear aperture – 250 mm;
Focal length – 2000 mm;
Primary substrate – fine annealed Supremax33; Quartz/Clearceram-HS/Zerodur (special order);
Secondary substrate – Quartz or fine annealed Supremax33;
OTA type – Serrurier Truss;
Aluminium alloy used – Type 70xx for plates; Type 60xx for anodized elements
Primary mirror cage – Carbon Fiber;
Truss tubes – Carbon Fiber.
700 (L) x 330 (l) x 330 (h) mm (might differ slightly, depending on extra items chosen);
Weight – 12.5 kg;
Back-focus from back plate ~ 220 mm;
Connection thread on the back plate adapter: M117x1 – male.
Included in the price of the OTA :
*D-type (Losmandy) dovetail, 300 mm long;
*upper handle or second dovetail (can be either D-type or V-type; Customer’s choice), 180 mm long;
*side plates for increased stiffness;
*finder bracket + riser;
*precision adjustment knob for secondary mirror with 0.5-mm or 1-mm travel per full turn, Customer’s choice;
*precision tilt knobs for primary mirror with 1-mm travel per full turn;
*primary mirror fans (RCA connector);
*primary mirror dew heater (RCA connector);
*secondary mirror dew heater (RCA connector);
*Lycra truss covers, set of 3 (three). Front, secondary case and truss cover;
*aluminium cover for primary’s cage;
*Field Corrector, corrected field is ~52 mm;
Supremax33 version – 6290 Euro, including VAT; Net price – 5114 Euro.
Quartz/Clearceram-HS/Zerodur – 7490 Euro, including VAT; Net price – 6089 Euro.
Optional items :
*flight case – 500 Euro, including VAT; Net price – 406 Euro.
*soft case – 195 Euro, including VAT; Net price – 159 Euro.
*focuser – various choices; please inquire for pricing.
We recommend FTF3215 as it can accept directly our Field Corrector.