Ritchey - Chretien 250mm

Availability: manufactured on request; Type: reflector

Our line of Ritchey-Chretien reflectors is designed to offer non-compromising imaging quality, by integrating everything needed in a package containing high-quality hand-figured optics, top-quality finish & mechanics.
We’re delivering the full range of substrates for these telescopes, starting with basic borosilicate glass (Supremax33), moving upwards in value/quality by using Ultra Low Expansion glass like Fused Silica/Quartz while for those of you who desire best optical quality finish, we do deliver also cellular blanks. The latter has the advantage of quickest cool down coupled with reduced weight (sensible weight differences/gains are observable in bigger sizes, 350 & 400mm).

Main features:
* hand-figured Ritchey - Chretien optics;
* precision adjustment of primary & secondary mirror;
* portable, medium size reflector telescope;
* truss type chassis design for quick cool down;
* carbon fiber and aluminium alloy high quality construction.

Specifications & technical data:
Clear aperture – 250 mm; Focal ratio – F/7; Focal length – 1750 mm; Central Obstruction – 48%, linear;
Clear aperture – 250 mm; Focal ratio – F/8; Focal length – 2000 mm; Central Obstruction – 45%, linear;
Primary substrate – Supremax33, Fused Silica/Quartz or Cellular;
Secondary substrate – Fused Silica/Quartz;
Primary mirror cage material – Carbon Fiber;
Truss tubes material – Carbon Fiber.

Dimensions:
F/7 version – 750 x 345 x 380 mm (L x l x h; considers handle and dovetail added height);
F/8 version – 800 x 345 x 380 mm (L x l x h; considers handle and dovetail added height);
Weight – ~13 kg;
Usable back-focus – ~235 mm, from back-plate;
Usable back-focus – 104.7 mm, from corrector, at F/7;
Usable back-focus – 98.5 mm, from corrector, at F/8.

Pricing (2019):
RC250 F/7,   7680 Euro, including VAT 23%. Net export price – 6244 Euro (non-EU countries) Supremax33 version
RC250 F/7,   8490 Euro, including VAT 23%. Net export price – 6902 Euro (non-EU countries) Fused Silica/Quartz version

RC250 F/8,   7380 Euro, including VAT 23%. Net export price – 6000 Euro (non-EU countries) Supremax33 version
RC250 F/8,   8190 Euro, including VAT 23%. Net export price – 6659 Euro (non-EU countries) Fused Silica/Quartz version
RC250 F/8,   9500 Euro, including VAT 23%. Net export price – 7724 Euro (non-EU countries) Cellular version

Included items:
– 3.2" Starlight Instruments focuser, rack and pinion, 38mm travel;
– Field Corrector, 44mm corrected circle diameter;
– shroud pack (secondary casing shroud, secondary cage shroud, truss shroud);
– side plates (pair);
– riser + finder shoe (Starlight FSB-CH);
– primary mirror cooling fans;
– primary mirror heater;
– primary mirror hard cover;
– secondary mirror heater;
– 350 mm D-type dovetail;
– handle.

Coatings:
standard coating reflectance: 92% (SiO overcoat), included in the price.
optional enhanced coating reflectance: 96% (TiO overcoat) = +210 €, including 23% VAT; net price = 171 €.

Optional accessories to consider when ordering:
Dovetail, Losmandy Type, 350 mm length, lightweight = 140 Euro, including VAT 23%; Net price = 114 Euro;
Padded case = 160 Euro, including VAT 23%; Net price = 130 Euro;
Dual controller for primary's heater and fans = 185 Euro, including VAT 23%; Net price = 150 Euro;
Electronic focusing package for secondary mirror = 800 Euro, including VAT 23%; Net price = 650 Euro;
Electronic focusing package for FTF3215, Focuser Boss II Kit (HSM30 motor + Controller) = 812 Euro, including VAT 23%; Net price = 660 Euro.

Visual accessories:
A prism or mirror diagonal will be needed, together with good quality eyepieces, to be able to extract the most of your new telescope.

Imaging accessories:
We can manufacture adapters and extensions to suit one's observing and/or imaging needs.

Number of units manufactured/ordered: 15
Number of F/7 units manufactured/ordered: 1
Number of F/8 units manufactured/ordered: 14
Units available for ordering: manufactured based on order.
Average lead time: please inquire.
Prices subject to change without notice.

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