Ritchey - Chretien 400mm

Availability: Manufactured on request Type: reflector

Our Ritchey-Chrétien reflector series is engineered for uncompromising imaging performance.
Each unit integrates all essential components into a precision-crafted package featuring hand-figured optics, premium mechanical construction, and a durable, long-lasting finish.
We offer a selection of optical substrates to suit a range of performance needs and budgets:

Supremax33 Borosilicate Glass (Schott) – Fine-annealed and cost-effective, ideal for entry-level applications.
Fused Silica / Quartz (Ohara's SK-1300) – Ultra Low Expansion (ULE) material with excellent thermal stability.
Clearceram-HS (Ohara) – glass ceramic material with ultimate level of thermal stability.

For apertures of 350 mm and above, we strongly recommend Fused Silica / Quartz or Clearceram-HS, both of which deliver superior thermal behaviour and exceptional optical surface quality.

Key features:
* Hand-figured Ritchey - Chretien optics
* Precision adjustment of primary & secondary mirror
* Observatory class reflector telescope
* Truss type chassis design for stability and quick cool down times.
* Carbon fibre and aluminium alloy, high quality chassis/frame.

Specifications & technical data:
Clear aperture – 400 mm; Focal ratio – F/8; Focal length – 3200 mm; Central Obstruction – 50%, linear
Primary substrate – Supremax33, Fused Silica/Quartz, Clearceram HS.
Secondary substrate – Supremax33, Fused Silica/Quartz, Clearceram-HS.

Dimensions:
1150 x 525 x 560 mm (L x W x H; considers handle, dovetail & focuser added height/length)
Weight = ~35 kg*
Usable back-focus = ~275 mm*, from back-plate
Usable back-focus = ~88.8 mm*, from corrector's last mechanical surface.
*Variations may occur with individually produced components.

Pricing :
starting from 13 900,00 Euro, net for Supremax33 version*
Price for Fused Silica/Quartz or Clearceram/Zerodur version - to be communicated at the time of ordering, based on raw blank quotes from our glass suppliers.

Included items:
– 3.5" Starlight Instruments focuser, rack and pinion, 38mm travel (model FTF-3515)
– Electronic focuser control for FTF3515 (motor with integrated controller, from Starlight Instruments)
– Field Corrector, 60mm 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
– 500 mm D-type dovetail (Losmandy)
– handle
– back-plate handles pair

Coatings:
standard coating reflectance: 92% (SiO overcoat), included in the price.

Optional accessories to consider when ordering:
Additional dovetail, Losmandy Type, lightweight, to replace the handle.
Controller for heaters and fans (several variants available for integration).

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:
Adapter rings are available to fit the thread dimensions of each supplied corrector.

Units available for ordering: manufactured to order.
Delivery time from order (approximative): 12 - 15 months.

* Prices subject to change without notice.
* Net prices are exclusive of any applicable duties and taxes.
These are the responsibility of the Buyer and may be charged by your local customs authority upon delivery.

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