Moon Image (Just past 1st Qtr)

This is an image of the Moon taken on Friday 19th April 22:20 at the WYAS Observatory.

Taken using a Celestron 8" SCT on the Large Pier with a Canon 40D DSLR, PC connected and operated via Canon EOS for remote DSLR control. The image was also taken using a f6.3 reducer, (see note below). 50 images taken at 1/640th sec at ISO 1250. These were then stacked in RAW image format using the older RegiStax 5. The image saved as a 16bit TIFF and was then opened in PhotoShop and lightened a little to give the final image. 

What is an f6.3 (f3.3) Focal Reducer:-

A focal reducer mounts directly to rear of a telescope and alters the field of view / focal length of the telescope for astrophotography. When an f6.3 reducer is fitted to an SCT which is normally f10 it reduces the f10 to f6.3 reducing the exposure time required to image a deep sky object. A typical 5 minutes exposure at f10 would be reduced to 3 minutes.  However, the focal length of the telescope is also reduced so the image object is reduced in size. A typical 8" SCT focal length 2000mm is reduced to 1260mm. This effectively provides a larger field of with within the DSLR image frame.  (The f3.3 does exactly the same changing an f10 to f3.3 but reducing a 2000mm focal length telescope to 660mm).