Charleston Lake
Astronomical
Imaging the Night Sky from Ontario Canada
ST-8300M CCD Camera
The SBIG ST8300M is a monochrome, 8.3megapixel, cooled dedicated astronomy camera. It was initially announced in 2010, and was produced for around 7 years, when it was replaced with the STF-8300. The STF-8300 is similiar, but has a faster USB speed (the F stands for Fast) and it has a dessicant plug.

The ST-8300 is typically operated at approx -15C during imaging, which reduces thermal noise in the CCD. The temperature is regulated for a constant temperature, allowing accurate image calibration with a library of dark frames and bias frames captured at the same temperature.

The CCD chip is the KAF-8300. It is full frame, 8.3megapixels, with 5.4um pixels, in a 22mm diagonal, 4/3 size format. The 8300 is, in my opinion, an under-rated CCD chip. It is large, sensitive, and with regulated cooling, exhibits low thermal noise.

The KAF-8300 CCD is approximately 18 x 14mm and has a diagonal measurement of about 22 millimeters. With its relatively small pixels and large image area it is ideal for wide field imaging with short fast refractors. Binned 2x2 the pixels are 10.8 microns square and binned 3x3 they are 16.2 microns square. At 2x2 the array is still 2 megapixels and at 3x3 just under one megapixel. This feature makes it possible to match the pixel size to your seeing and scope, from a small refractor to a large SCT. For most users, binning will not only help optimize the sensitivity of the CCD with their optics but also speed up the download rate.

Why collect data with a monochrome sensor? There is an increase in quantum efficiency without filters. All colour CCD and CMOS chips have a Bayer Filter array on the chip, which reduces the light gathered by approximately 60%.

The mono CCD is a more efficient way to collect photons than a Colour Matrix CCD. In a given exposure time, more data is gathered. It can then be combined as a Luminance layer, with RGB data, for a final color image.

The KAF-8300 CCD chip was quite popular for Astronomy cameras, with thousands of these CCD chips still in use, from multiple manufacturers of Astronomy CCD cameras. 

While ONSemi has discontinued the KAF-8300 CCD, that means no new cameras will be produced using this CCD chip. With appropriate care, the existing 8300 cameras have a long life ahead, as they can last for thousands of image cycles.
M31 in monochrome - imaged with the ST8300M
KAF-8300 Specifications
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(Original SBIG Document)
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