Purpose-built for astrophotography: a fast 206 mm aperture, f/2.72 astrograph delivering ~560 mm focal length for wide-field nebulae, comets, large galaxies, and mosaics without sacrificing fine structure.
Full-frame imaging ready: a 44 mm corrected image circle with a matched 4-element apochromatic corrector (includes one super-ED element) keeps stars tight to the corners.
Premium optics, proven by metrology: fused-silica primary (hyperboloid) and plane secondary are verified on interferometers and eccentricity meters to ensure top-tier figure and alignment.
Mechanical precision for repeatable results: 2.5" dual-speed focuser is thread-coupled to the corrector, integrates a dedicated bearing rotator (CAA) with angle scale, and includes a focal-plane adjustment device for easy orthogonality/tilt tuning.
Designed to hold focus and kill flex: 4 mm carbon-fiber tube, CNC aluminum clamping hoop (10 mm thick, 22 mm wide), and carefully positioned support points deliver rock-solid rigidity for long imaging runs.
Built-in anti-dew strategy: micro-heating dew removal plus the included OCAL anti-dew system protect critical optics through temperature swings and high humidity.
Imaging-friendly backfocus: 55 mm from the corrector to the sensor, with M48×0.75 and M54×0.75 adapter rings for straightforward camera train integration (filter wheels, OAGs, spacers).
Field-smart layout: 80 mm secondary sized for illumination, Noctutec German anti-reflection paint on the tube interior for superior stray-light control, and smooth, resistance-free rotation for perfect framing.
Compact, travelable package with pro-grade protection: short overall length, robust build, and a wheeled aluminum case for dark-site convenience.
Specifications
Model: OCAL H-2 (H-206)
Optical Design: Hyperbolic Newtonian astrograph
Aperture: 206mm
Focal Ratio:f/2.72
Focal Length:~560 mm
Image Circle:44 mm full-frame
Secondary Mirror (minor axis):80 mm
Primary/Secondary Substrate:Fused silica glass
Primary/Secondary Figure:Hyperboloid / Plane
Corrector:4-element APO, one super-ED; clear aperture 56 mm; adapters M48×0.75 & M54×0.75; backfocus 55 mm
Focuser:2.5" dual-speed, threaded to corrector; bearing CAA rotator with angle scale; focal-plane adjustment device
Tube Material:Carbon fiber, 4 mm wall
Tube Interior:Noctutec special anti-reflection coating
Mounting Rings: CNC aluminum, 10 mm thick, 22 mm wide, Ø 254 mm; 10× M6 threaded holes
Dimensions:Length 630 mm; tube Ø 254 mm; max distance between dovetail plates 340 mm
Weight (complete bare set):12.7 kg
Dew Control:Micro-heating dew removal design
What’s in the box?
OCAL H-2 telescope main body (tube clamp, dovetail plate, focuser, matched corrector)
OCAL anti-dew system
Wheeled aluminum carry case
Quick Start Guide
Screwdrivers and hex wrenches for collimation/adjustment
