Classic Cassegrain 350 mm

Availability: Manufactured on request Type: reflector

Our Cassegrain reflectors are designed for high-quality visual astronomy, with strong performance in planetary and lunar observation, as well as deep-sky targets such as globular clusters and nebulae. They are also well-suited for planetary imaging.
Each unit combines effective light-gathering capability with carefully crafted mirrors housed in a precision-engineered chassis, allowing for straightforward and stable collimation.
Despite common misconceptions, properly designed and executed Cassegrain optics can produce coma-free, pinpoint star images across the field of view, whether using 1.25″ and 2″ eyepieces.
We offer a comprehensive 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:
* 2" rack and pinion type focuser from Starlight Instruments, 50mm travel
* Precision adjustment of primary & secondary mirror
* Portable, medium size 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 – 350 mm; Focal ratio – F/15; Focal length – 5250 mm; Central Obstruction – 29%, linear
Clear aperture – 350 mm; Focal ratio – F/17; Focal length – 5950 mm; Central Obstruction – 26%, linear
Clear aperture – 350 mm; Focal ratio – F/20; Focal length – 7000 mm; Central Obstruction – 23%, linear
Primary substrate – Supremax33, Fused Silica/Quartz, Clearceram HS.
Secondary substrate – Supremax33, Fused Silica/Quartz, Clearceram-HS.

Dimensions:
F/15 version – 1120 x 450 x 490 mm (L x W x H)
F/17 version – 1130 x 450 x 490 mm (L x W x H)
F/20 version – 1150 x 450 x 490 mm (L x W x H)
Weight = ~22 kg*
Usable back-focus = ~190 mm*
*Variations may occur with individually produced components.

Pricing:
starting from 9 500,00 Euro, net for Supremax33 version*
Price for Fused Silica/Quartz or Clearceram/Zerodur version - to be communicated at the time of order, based on raw blank quotes from our glass suppliers.

Included items:
– 2" Starlight Instruments focuser, rack and pinion, 50mm travel (model FTF-2020RP)
– 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
– 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).
Electronic focusing package for FTF-2020RP using Starlight's HSM30 motors.
Controllers can be supplied by us or user supplied.

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.

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