Sometimes referred to as Electronic Light Control, electronic shuttering controls the amount of time a CCD camera collects light or charge during each field. Standard signal formats employ approximately 60 fields per second, the camera collecting charge for 1/60 second for each field. As light levels increase the sensor overfills with charge, resulting in blooming or streaking. Electronic shuttering circuits prevent these effects by allowing the sensor to collect charge for a shorter period during each field. Steps in shuttering generally halve the previous collection time; for example, from 1/60 second to 1/125, then 1/250, 1/500,1/1000, etc. (These steps correspond to unit f-stop increments, f/1, f/2, f/3...)