Ritchey - Chretien 250mm

Availability: Product sold-out; Type: reflector

* This product has been discontinued; no new orders accepted*

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, which we highly recommend as first choice for telescopes with 350mm and above diameters, while for those of you who desire best optical quality finish coupled with the lowest mass, we might be able soon to 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 – 50%, linear
Clear aperture – 250 mm; Focal ratio – F/8; Focal length – 2000 mm; Central Obstruction – 52%, 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 W x H)
F/8 version – 800 x 345 x 380 mm (L x W x H)
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 (last update in 2019):
RC250 F/7, 7 680,00 Euro, including VAT 23%. Net export price – 6 244,00 Euro (non-EU countries) – Supremax33 version
RC250 F/7, 8 490,00 Euro, including VAT 23%. Net export price – 6 902,00 Euro (non-EU countries) – Fused Silica/Quartz version

RC250 F/8, 7 380,00 Euro, including VAT 23%. Net export price – 6 000,00 Euro (non-EU countries) – Supremax33 version
RC250 F/8, 8 190,00 Euro, including VAT 23%. Net export price – 6 659,00 Euro (non-EU countries) – Fused Silica/Quartz version
RC250 F/8, 9 500,00 Euro, including VAT 23%. Net export price – 7 724,00 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) = +210,00 Euro, including 23% VAT; net price = 171,00 Euro.

Optional accessories to consider when ordering:
Dovetail, Losmandy Type, 350 mm length, lightweight = 140,00 Euro, including VAT 23%; Net price = 114,00 Euro
Padded case = 160,00 Euro, including VAT 23%; Net price = 130,00 Euro
Dual controller for primary's heater and fans (manual control) = 185,00 Euro, including VAT 23%; Net price = 150,00 Euro
Electronic focusing package for secondary mirror = 800,00 Euro, including VAT 23%; Net price = 650,00 Euro
Electronic focusing package for FTF3215, Focuser Boss II Kit (HSM30 motor + Controller) = 812,00 Euro, including VAT 23%; Net price = 660,00 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: 17
Number of F/7 units manufactured/ordered: 2
Number of F/8 units manufactured/ordered: 15
Units available for ordering: none, product unavailable for ordering, starting with October 2020.

* Prices subject to change without notice.

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