Professional Telescopes


Telescopes and Instruments "RiDK​"

The "universal" telescope. With a balanced f/7 focal ratio and the 2-lens field flattener

it offers a good compromise between obstruction and focal ratio. Two-stage light shield as standard on the secondary mirror, allows lower obstruction for the same focal plane illumination. Reducer available for f/5 operation.

RiDK 400

Overview "RiDK​" SERIE

An evolution of the Dall-Kirkham design, the RiDK is probably the most “universal” family in our catalog, and the most affordable. With a f/7 native focal ratio, the RiDK (Riccardi Dall-Kirkham) represents the new reference point for all modified Dall-Kirkham instruments available on the market.

The unique experience and creativity of Massimo Riccardi, Chief Optical Designer at Officina Stellare, created this new family of telescopes. with superior performance and image quality.

The results are simply amazing: a telescope that offers a wide, flat focal plane (more than 65 mm in diameter, even in the smallest model!). A wide focal plane that is diffraction limited over a wide spectral range.

Since the corrector group is close to the focal plane, chromatic aberration is undetectable.

ENTRY PUPIL DIAMETER From 400 mm (16'') to 800 mm (32'')
FOCAL LENGTH From 3200 mm (126'') to 6400 mm (252'')
From 60 mm to 90 mm
WEIGHT From 40 Kg to 180 Kg
BACK FOCUS EXTRACTION From about 220 mm (8.6'') to about 300 mm (12'')


Low expansion glass optical set, carbon/aluminum truss tube design, splitted light baffle, four support dovetails, three ventilation fans and mirrors heaters with manual control, shroud and cap covers. Primary cell detachable for an easy cleaning of mirror.

AVAILABLE IN FULL CARBON, ATHERMIC LIGHTWEIGHT TRUSS TUBE. Optional accessories: 0.75x reducer, digital or manual back plate focusers (only for 400mm), rotators, secondary mirror focuser (from 500mm), mirror shutters, OS Bus advanced electronic, customized imaging train parts and more. Available also with Officina Stellare mount.

All telescopes share the following mechanical characteristics:

  • Two (optionally four) Losmandy or 8″ dovetail plates, to connect the telescope to your mount, or to accommodate accessories.
  • Computer optimized baffles.
  • Focal plane tilt adjusting.
  • Optional shutter to protect the primary mirror.
  • High precision spherical joint and high strength carbon tubes in the truss structure for zero-backlash assembly and extraordinary rigidity.
  • Double concentric light shield for the secondary mirror/spider support.
  • Radial micrometric adjustment for the secondary mirror support.
  • All collimation screws are spring-loaded, with lock if needed.
  • Zero image shift secondary mirror movement, with electronic/PC control (optional on smaller telescopes, standard in the big ones).
  • Special ultra-dark and ultra-opaque space-grade paint for all sensible parts. Space grade glue for glued parts. Space-grade rubber for all seals.
  • Unique mirror supports design.
  • Wide choice of focusers, filter wheels, and optical train accessories in general.
  • Customization available.