Sub-sampling
Sub-sampling is the process of skipping neighboring pixels (with the same color) while being read out from the CMOS or CCD chip. CMOS equipped MARLIN models, both color and b/w have this feature (FW > 2.03). E.g. the CCD model MARLIN F-146C is also equipped with this mode, acting as a preview mode. Because it is realized digitally there is no further speed increase.
Sub-sampling is used primarily for 2 reasons:
A reduction in the number of pixels and thus the amount of data while retaining the original image area angle and image brightness
CMOS: an increase in the frame rate.
Similar to binning mode the cameras support horizontal, vertical and h+v sub-sampling mode.