Starlight Xpress CoStar - Manual (Page 2)

CoStar handbook Issue 1 May 2011
The CoStar control software is CoStar.exe and the latest version may be downloaded from the Starlight
Xpress web site (
http://www.starlight-xpress.co.uk ), if necessary. Copy the exe file and dlls into a
folder on drive C and run the exe file to start the software. Alternatively, both ‘PHD’ and ‘Nebulosity2’
support the CoStar and may be preferred. An ‘ASCOM’ driver is available for use with the CoStar (and
other SX cameras). This allows you to use Maxim DL and other ASCOM compatible software, if you
wish. Please visit
http://www.daddog.com/ascom/sx/index.html to download the latest version.
The USB and guider output connectors
Using the CoStar:
The CoStar is generally used with a separate guide telescope, or via an off-axis guider. It is designed to
be inserted into a standard 1.25” focuser assembly, but also has a 25mm ‘C’ type camera lens thread in
the front to allow standard CCTV lenses to be attached. Please note that the chip to lens distance is
only 12.5mm and so a ‘CS’ to ‘C’ extension will be needed to permit a standard C lens to reach focus.
Lenses designed for ‘CS’ mount cameras will focus without an extension tube, but many of these
lenses cannot fully illuminate a half-inch format chip, so take care when selecting a lens for this
purpose.
A typical set up might consist of an inexpensive 80mm F5 refractor ‘piggybacked’ onto an SCT, with
the CoStar fitted directly into its focus barrel. Many such telescopes are designed to be used with an
inverting prism ahead of the eyepiece and so the focuser may be too short when the CoStar is inserted
directly. In this case, an extension tube may often be made from a cheap Barlow lens assembly with the
lens removed. This configuration can be seen in the picture below.