The QSI 540c camera employs a 4.2 megapixel Kodak KAI-04022 interline transfer CCD image sensor with microlens technology. Integral Bayer RGB colour filter array allows Single-Shot colour imaging. The high quantum efficiency, wide dynamic range and low noise performance make the 540c ideally suited to a broad range of demanding astronomical, scientific and industrial imaging applications. The 21.4mm diagonal CCD in the 540c provides the largest field of view available in the QSI 500 Series. Electronic Shutter All 540c models utilize the electronic shutter built into the KAI-04022 CCD image sensor to control exposures. Shutter timing is very precise and can range from as short as 100 microseconds up to 240 minutes. Mechanical Shutter The Model 540cs camera adds 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.