The Wallace 24-inchTelescope

picture of 24-in

General Information

The 24-in telescope at Wallace is an Ealing "24-in Research Cassegrain Coudé" reflector on an asymmetric German equatorial mount. The image scale is 22.04 arcsec/mm at its f/15.6 Cassegrain focus. Focal length is 9,360mm at each of the four ports of the instrument selector.

In 2009, the entire optical system was removed to be recoated. During that time the entire mechanical system was refurbished.

Telescope movement is controlled by a PC-DOS computer system running MOVE, a application developed by Larry Wasserman at Lowell Observatory in Flagstaff, Arizona, and which he has adapted for use with this telescope. This control system was to be replaced by a custom ChronosMount Inc., operating system running on a 64-bit Windows 7 machine. This system failed and will soon be replaced by a more reliable, widely used telescope control system.

The 24-in telescope was built as the centerpiece of the observatory in 1971. In its Cassegrain configuration it's been the telescope most used for research at Wallace and several papers and theses have been published using data obtained with it.

More information


On an Optec Perseus Instrument Selector we have an SBIG STL1001E Camera and an Optec NexGen 0.7 3" Telecompressor, an FLI Microline ML0251E CCD "PICO", Andor Ixon 777 "POETS" and a T-thread mount for eyepieces and DSLR cameras.

Other Ealing telescopes:

Our 24-in telescope is Ealing serial number 207. We've been told by Paul Valleli, an optical engineer who used to work for Ealing, that probably 7 or 8 of the 24-in telescopes of similar type were built. We found some information about a couple of them on the Web: