What is Partial Scan?
Partial scan is a readout mode, whereby only a part of the CCD is read out. The remaining lines are “fast dumped” out of the image sensor and ignored. This results in a higher frame rate, with reduced vertical resolution. Typically, partial scan is defined as 1/2, 1/4, 1/3, 1/8, etc. of the full resolution, located in the middle of the imager. Some camera models have user selectable start position and number of lines in partial scan. CMOS imagers also allow partial scan, where a region of interest can be defined both in the vertical and horizontal direction. This is normally referred to as windowing.
