I have a atik ccd 383l and I if want to use a meade focal reducer 6.3 with my 14'' sct do I need to add a spacers and work out a back focus distance between reducer and ccd. any help much appreciated
regards J G
John if its a regular XLT then probably not if its a HD then you will . Celestron have a chart that shows backfocus distance and FOV coverage , look that up mate.