Buying a high quality Celestron SCT or EdgeHD will give you great views of the Moon, planets and deep sky objects. However if the telescope optics are not properly aligned – or collimated – the views of objects will appear soft and you will be unable to achieve sharp focus.
We get regular enquiries on how to collimate and SCT/EdgeHD and its often difficult to explain over the phone as to what is needed to be done. Celestron have recently written a SCT/EdgeHD collimation guide that covers the process in detail and step by step. For those interested in this important and critical process see their article here.