Warning: Please note this section describes a CCD-specific feature. This feature is not available on modern sCMOS-based cameras.

A frame transfer CCD is divided into two areas: one for image collection and one for image storage. After the CCD is exposed, the image is shifted to the storage array that is not light sensitive. A split clock allows the CCD to expose the next frame of the image array while simultaneously reading out from the storage array. Since shifting an image to the storage array is many times faster than reading out the same image, frame transfer speeds up many sequences, in comparison to full frame sensors. With most frame transfer CCDs, the image in the storage array must be completely read out before the next image is shifted into the storage array. Therefore, assuming that the exposure_time for each image within a sequence is equal, the shortest possible exposure_time would be exactly equal to the image readout time.