The QSI 520c camera employs a 2 megapixel Kodak interline transfer CCD image sensor with microlens technology. Integral Bayer RGB colour filer mask allows Single-Shot colour imaging. The high quantum efficiency, wide dynamic range and low noise performance make the 520c ideally suited to a broad range of demanding astronomical, scientific and industrial imaging applications. Electronic Shutter The 520ci utilizes the electronic shutter built into the KAI-2020CM CCD image sensor to control exposures. Shutter timing is very precise and can range from as short as 100 microseconds up to 240 minutes. 520cs adds Mechanical Shutter The Model 520cs camera incorporates the optional internal mechanical shutter in the 'mid-size' camera body configuration. When operating with an interline transfer CCD, a mechanical shutter is not used to actually make the exposure. This is still the responsibility of the electronic shutter. The mechanical shutter is employed to cover the CCD and simplify the creation of Dark and Bias frames for subsequent image processing. Single-Shot Colour Imaging Single-Shot colour imaging is made possible by overlaying the pixels on the CCD with an alternating red, green and blue colour filter matrix at the time of manufacture. This is the same technique used by the vast majority of colour video and still cameras to create colour images. Single-shot colour imaging eliminates the need to take a sequence of images through multiple colour filters and is essential for applications with moving subjects.