Equipment - backyard- observation place
observation place
My observing place is in my garden with a bortle 6 - 7 sky. If you observe from the city, unfortunately you must accept restrictions ;-)....a consolation, I have good observing conditions in the zenith...
Celestron RASA 8 f/2 Rowe-Ackermann Schmidt Astrograph
The Celestron 8 f/2 RASA is a dedicated instrument, it can only be used at f/2 like a Schmidt-Camera. Unlike the larger RASAs that work with DSLR and large CCD cameras, the 8” model was designed with color astronomical CMOS cameras, smaller CCD cameras, and mirrorless cameras in mind. The telescope does not work with standard DSLR cameras.
Celestron RASA 8 f/2
Disadvantages... if necessary very difficulty in collimation, often refocusing per session, focusing it at f/2 will be a nightmare, but, I'm assuming I'll use autofocus later.
Advantages... shifting free, fast saturated images, small stars, going from f/7 (C11 EdgeHD with reducer) means 10x shorter subs
Celestron RASA 8 f/2 with Celestron LPS nebula filter and Baader FCCT
...with Baader FCCT prototype and Light Pollution Imaging Filter. The Celestron LPS nebula filter increases contrast by suppressing stray light
Celestron RASA 8 Celestron Focus Motor
The Celestron Focus Motor enables electronic focusing using a computer or Celestron computerized mount hand controller for remote/hands-free observing.
Takahashi Mewlon 210
The focal length of this particular model Takahashi Mewlon 210 is 2415mm (F11.5) native, a simple reducer/corrector brings it to 1961mm (F9.3), metal back distance 67.2mm without reducer, metal back distance 56.2mm with reducer. The Mewlon is a Dall-Kirkham design with a spherical secondary, in contrast to the RC. This supposedly makes it easier to make and easier to keep collimated - an area of telescope design I leave to the experts at Takahashi to decide, since they also make the RC based design scopes.
The precision optical surfaces of the Mewlon 210 is at least λ/20. This results a highly concentrated airy disc, resulting in pin point star images and high contrast fields. The primary mirror is installed in a specially designed mirror cell that is designed to reduce astigmatism.
