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G2 cameras with Kodak KAI Interline Transfer (IT) architecture.
There is a shielded column of pixels just beside each column of active
pixels on these detectors. The shielded columns are called Vertical
registers. One pulse moves charge from exposed pixels to shielded
pixels on the end of each exposure. The the charge is moved from
vertical registers to horizontal register and digitized in the same way
like in the case of Full Frame detectors. This mechanism is also known
as “electronic shuttering”, because it allows very short exposures and
also digitization of the image without mechanically shielding of the
detector from incoming light.
Also G2 cameras with IT CCDs are equipped with mechanical shutter,
because electronic shutter does not allow dark-frame exposures,
necessary for proper image calibration etc.
The price for electronic shutter if lower quantum efficiency
(sensitivity) of IT detectors compared to FF ones. Also all IT detectors
are equipped with ABG, so they can acquire images of very bright
objects without charge blooming to neighboring pixels.
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Illustration 4: “Interline Transfer” CCD schematic diagram
