A harvester includes a feed system operable at a feed speed and configured to feed a crop towards a blade. The blade is configured to cut the crop into crop billet and is operable at a cutting speed. The harvester further includes an optical sensor configured to generate a signal corresponding to a length of the crop billet and a control system with a processor, a memory, and a human-machine interface. The control system is configured to receive the signal and programmed to adjust one or both of the cutting speed or the feed speed based on the signal.