Prime Focus Newtonian 500

We offer a series of very fast yet very well corrected Newtonians. By eliminating the necessarily large secondary mirror of a fast newtonian system we achieve razor sharp images in a relatively simple optical system.

The prime focus series telescopes are available in f/3.3 and have a sub-aperture corrector. Focus is achieved by moving the primary mirror. With only one mirror of exceptional quality < 1/8 th PTV, these instruments are perfectly suited for fast astrophotography.

Price (Excl.VAT)


Aperture (mm)500
Recommended mount typeGEM
Tube tubeClosed
Focal length (mm)1650
Tube length (transport)1500
Tube length (operating)1800
OTA Weight (kg)60
Back focus150
Focal ratio F/3.3
Fully corrected imaging circle (mm)50
Cooling fansPrimary mirror
AirflowLaminar flow & Rear
Mirror coatingsEnhanced Aluminium + SiO2 protective layer
FocuserIntegrated JTW Rhino
Tube constructionCarbon fiber
Optical surface quality (Strehl, PTV)0.97, 1/10
Primary mirror substrateSchott Supremax 33
Primary mirror cell18 point floatation cell
Primary mirror edge support6 point athermalised
Primary baffleOTA baffles
CorrectorIntegrated 3-element
BoltingA4 Stainless steel
Metal protectionDual
Surface treatmentAluminium – 20 micron hard-coat anodising
PaintExterior grade powdercoat (environmentally friendly)
Anti dew systemOptional