See last paragraph for new mention.
For nearly twenty years I spent my time as an amateur astronomer star hopping around the sky in search of, and finding many of those thousands of Deep Sky objects. When I decided to take up Supernova patrol work I realized that a 25cm aperture reflector used visually did not have enough light gathering power to see stars of 15 to 17th magnitude.Now all but the few brighter of the Supernova outbursts peak at around the 16th magnitude so I decided to do prime focus astrophotography to capture the fainter stars on film and possibly make a discovery. This became an obsession but at the same time was very time consuming. Also only a small number of galaxies could be recorded on film each night. The film development and field checking was tiresome after an all night session.In 1995, enough was enough for me. The age of the amateur CCD fast imaging cameras and electronic astronomy had began to take off. I decided to purchase the "Starlight Express" CCD imager complete with frame store and image processing software. I used it to great advantage and am never likely to switch back to photography except for the really wide fields required for the bright comets and recording Meteors. The speed to do my supernova patrol work and record faint deep sky objects using the CCD camera was greatly enhanced by purchasing the computerized Meade LX200 25cm F10 Schmidt Cassegrain reflector. To give me a larger field ( approx 2x larger) I added the Giant Lumicon F6.3 focal reducer to the prime focus. The telescope is permanently housed and this makes for accurate alignment. The alignment and tracking was exceptionally easy to set up with the Meade system. The Polar alignment took just a few hour and has never needed to be adjusted since the first day. The periodic errors were easily ironed out using the telescopes "Smart Drive" learn system. In fact the worm takes about 8 minutes to do a full 360 degree rotation in Right Ascension. I did a test for tracking using a magnification of 577 times using a high power cross hair eyepiece and a Barlow lens. After 10 minutes the guide star at the cross hair was still at dead centre. Good news for the CCD user. The longest CCD exposures I normally ever did using the Starlight Express SX and frame store CCD camera was around 512 seconds. Most of my exposures of 256 seconds duration recorded 18th magnitude stars on clear Moonless nights. The telescope has a data base of 64.359 stellar objects. The pointing accuracy of the telescope is capable of putting the selected object into the field of view to within 2 minutes of arc for any position in the sky. This means, using the Meade "Start Find" and "Precision Pointing" commands the objects selected always fall very close to the centre of the CCD chip, so therefore appears close to the centre of the monitor every time.
NEW year 2000.
Starlight Express CCD. "The MX916 USB with Star2000 Autoguider".
I still use the Mead 25cm LX200 telescope at prime focus. It is now however a fully robotic supernova patrol instrument. The new Starlight Express camera and software, and a telescope which receives commands to automatically go to chosen galaxy lists work together via networking from inside my home to the observatory. It is warm every night and very productive and fast indeed. The new CCD camera from Starlight Express and scope and camera controller software program that my friend John Rock wrote for me have made this all possible. I simply type out a script file of a list of target objects and away it goes automatically all night long. I decided to upgrade to the MX916USB camera and Star2000 autoguider software. The camera is more sensitive than my previous SX framestore camera. My USB version downloads images in one to a few seconds. The autoguider is capable of locking onto a guide star and keeping it in position on the chip with offsets better than a 1 pixel on most nights. 2 of 3 pixel errors when atmospheric turbulance is bad. One pixel in high resolution camera mode is a mere 1.88" by 1.81" seconds of arc. In non high resolution camera mode the pixels are 3.75" by 3.62" seconds of arc. My present field of view using a focal reducer at prime focus gives me a field image size of of 23.50' by 17.50' minutes of arc. The autoguider can also track on moving objects such as comets. Star2000 Autoguider can stop a fast moving object in its track and demonstrate how much it moves across the sky. I will add though that due to perfect polar alignment and the smart drive corrections that the telescope does not need the autoguider on any exposure up to and past the 8.5 minute rotational period of the RA worm over the full 360 degrees. Example, See: Near Earth Asteroid 1998 WT24 in Comet and Solar System image library. I will not say any more except I am a very happy customer. Well done Starlight Express. United Kingdom.
Please visit the Starlight express Homepages for all the latest information on the products available. The ultimate in astronomical Imaging.
Excellent book on CCD astronomy. "The Art and Science of CCD Astronomy". David Ratledge (ed.) ISBN 3-540-76103-9
Mount Tuffley Observatory.Chapter 2."Small Astronomical Observatories" P.Moore Ed) ISBN3-540-19913-6 Including many fine amateur observatories.