Celestron’s wide field, fast F/2, 8″ aperture Rowe-Ackermann Schmidt Astrograph (RASA) telescope is proving to be extremely popular. It’s small size and relatively low weight makes the instrument an ideal choice for those wanting to do astrophotography on relatively low cost medium sized mounts. A set up such as the RASA 8 with the Celestron Advanced VX mount makes an ideal portable astrophotography system that is easy to take away to your favourite dark sky spot(s) to capture many deep sky splendours.
Mirrorless interchangeable lens cameras (MILC) are becoming popular over their heavier bulkier traditional DSLR counterparts, even for astrophotography, and the 8” RASA model was designed for use with such cameras (as well as small CMOS based astro-imaging cameras too). The MILC’s small size will cause minimal obstruction when attached and, alongside their sensitive imaging sensors, make a great match with the RASA 8″. Another benefit of using a mirrorless camera is that there are no power and/or data cables in the way which can cause (sometimes odd) diffraction spikes. In order to use a mirrorless camera you will need one of Celestron’s camera adaptors for the RASA 8″.
There are two MILC adaptors available: one for Canon cameras,
and one for Sony cameras.
These MILC adaptors:
- Are made so that the camera’s sensor is placed at the precise backfocus distance for best image quality.
- Are similar in appearance to the T-2 and C-thread camera adaptors supplied as standard with the RASA 8, except of course they use the brand-specific camera bayonet mount for camera attachment, and are secured to the RASA lens group cell with the knurled retaining lock ring.
- Have three slotted elongated holes to allow collimation to be undertaken if required.
- Have a small elongated hole that allows the adaptor to be removed from the camera using the (supplied) “T”-shaped tool. The pointed end of the tool is inserted through the hole which then presses the lens release button on the camera body allowing the adaptor’s removal.
Full instructions on using the camera adaptors can be found here.