Alpha Draconis 10 inch Folded Refractor OTAs

Product Description: 

These Folded Optical Tube Assemblies provide both high resolution imaging performance and the good light grasp of a 10 inch aperture. Because the tubes are fully enclosed and fitted with internal light baffles (coated with our proprietary Deep Sky Black TM low reflectivity surface coating), these telescopes offer exceptionally high image contrast. The 10-in. Alpha Draconis Folded OTA is offered in Standard Achromatic and Full Apochromatic versions. All optical elements are fabricated from precision annealed Schott Grade A optical glass blanks and are hand figured by laser autocollimation testing against a NIST certified optical flat mirror in our own USA facilities. Both versions incorporate fully adjustable objective cell assemblies, 2-stage coarse/fine focussers with squaring-on adjustments and a 120 mm aperture refractor finder/guide telescope. Folding flat first surface mirrors of 8-in. and 6-in diameters are placed so as to reduce the overall length of the tube assembly to approximately 1/3 that of the Alpha Draconis 10-in. standard OTA. The OTA structure consists of a fully enclosed rectangular truss tube with extensive internal stray light baffling. The objective lens is shielded by a baffled dewcap/lightshade extension tube. An adjustable longitudinal trim weight is provided for fine balance compensation of focal plane accessories.


Objectives: 10 inch (250mm) Fraunhofer achromat or 5 element apochromat

Focal ratio: F12 focal length 120 inches (3048mm)

Tube diameter: 16 x 25 x 44 inches (406 x 635 x 1117mm)

Overall length: 136 inches (1422mm)

Focusing: 8 inch (200mm) rack and pinion draw tube with capstan screw fine focus

Eyepieces: 2/1.25 inch

Weight: 272 pounds (124 kilos)


Achromat: from $41,250 ex-works

Apochromat: from $99,600 ex-works

Imports to UK attract approximately 6.5% import duty and 20% VAT plus shipping