Cassegrain Telescopes

Choosing a Cassegrain telescope: optical purity and high performance

The Cassegrain folds the light path using two mirrors, directing the beam straight to the rear of the tube. This all-reflective design needs no front lens, eliminating chromatic aberration and making it far less susceptible to night-time moisture than closed optical designs.

The different designs in the range:

• Classic long-focal-length Cassegrains (f/12): The benchmark design for high-resolution visual observing and imaging planets or lunar craters (notably from GSO). Their long native focal length makes additional amplifying lenses unnecessary for achieving high magnification.

• Corrected astrographs (such as the Sharpstar SCA310): Equipped with an integrated rear corrector group, they offer a perfectly flat field and sharp stars right into the corners of full-frame imaging sensors.

• Ultra-fast observatory astrographs (PlaneWave DeltaRho f/3): Designed for demanding permanent installations, they combine a very fast focal ratio with a rear focal plane. This layout enables extremely fast deep-sky imaging while simplifying cabling and the handling of heavy cameras.
  
  

Whether you want the sharpness of a planetary optical tube or the speed of a large automated astrograph, benefit from our advice on choosing the right mount capacity and mechanical adapters.