Corrected Dall Kirkham 250

300mm f/6 MDDK Astrograph
600mm - 1000mm mm f/5.6 ECDKs

The Enhanced Corrected Dall-Kirkham (ECDK) telescope is our workhorse. This is the most economical route to a high performance telescope, often the performance of an RC is not needed, ECDKs are easier to manufacture and therefore are very cost effective. The tube assembly is semi-ruggedised and is of fail-safe construction.

The mirror supports in instruments under 600 mm are high precision floatation cells with full edge supports, larger mirrors are supported with kinematic face and edge supports. The focuser is included as standard, this is achieved by moving the secondary mirror. The ECDK includes a 2 element corrector with optional 3-element system and integrated ADC.

Price (Excl.VAT)


Aperture (mm)250
Recommended mount typeGEM
Tube tubeClosed
Focal length (mm)1375
OTA Weight (kg)12
Back focus175
Focal ratio F/5.5
Fully corrected imaging circle (mm)45
Cooling fansPrimary mirror
Mirror coatingsEnhanced Aluminium + SiO2 protective layer
FocuserIntegrated JTW Rhino
Clear aperture (mm)50
Tube constructionCarbon fiber
Optical surface quality (Strehl, PTV)0.97, 1/10
Primary mirror substrateSchott Supremax 33
Primary mirror cell9 point floatation cell
Primary baffleSolid with micro-baffling
Secondary mirror substrateSchott Supremax 33
Secondary mirror cell3 point floatation cell
Secondary baffleSolid with micro-baffling
BoltingA4 Stainless steel
Metal protectionDual
Surface treatmentAluminium – 20 micron hard-coat anodising
PaintExterior grade powdercoat (environmentally friendly)
Anti dew systemOptional