Ultrastar C handbook Issue 1, August 2015
Handbook for the SX ‘Ultrastar C’ single-shot colour imaging and guiding
camera
Thank you for purchasing a Starlight Xpress ‘Ultrastar C’ camera. We hope that you will be very
pleased with the performance of this product.
The Ultrastar C is a higher QE and larger area version of the very popular ‘Superstar C’ and is a very
compact imaging camera, which is powered and operated via a single USB2.0 computer connection. It
also provides an opto-isolated output connection for direct control of most mounts, via their
‘Autoguider’ sockets. This output is compatible with the ‘ST4’ style of RJ12 connection and supplies 4
‘pull down’ direction lines and a common return. Alternatively, you may send the mount control
signals via a serial connection from the guider control computer. The Ultrastar C utilises a very
sensitive Sony ‘ExView2’ CCD (the ICX825AQA) with an array of 1392 x 1040 pixels in a ‘two-
thirds-inch’ format. Although the chip is not cooled, it has a very low dark signal and very little
readout noise, so it can be used to guide on faint stars that are well beyond the reach of webcams and
most CMOS chip based cameras.
The Ultrastar C specification:
CCD
-
Sony ICX825AQA ExView2 Bayer Matrix colour CCD
Pixel count
-
1392(H) x 1040(V)
Pixel size
-
6.45 x 6.45uM
Optical size
-
8.98 x 6.71 mm
Colour filter grid -
RGGB Bayer Matrix
Read noise
-
Typically 5.0 electrons
QE
-
Peak QE 70% (yellow light)
Gain
-
0.3 e/ADU
