Specifications

● G3 cameras with Truesense Imaging KAI Interline Transfer

(IT) architecture (G4 cameras are not produced with IT

detectors). 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 G3 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.

Illustration 2: “Interline Transfer” CCD schematic diagram