Open flash is a method of flash photography where the sequence of operation involves opening the camera shutter, firing the flash, and then closing the shutter. In this technique, the shutter duration is usually less critical because the flash provides the dominant light, far brighter than the ambient illumination.
Open flash is commonly used in studio and on-location photography where precise timing is needed to capture motion or freeze action. It allows photographers to control exposure primarily with the flash output, making it ideal for situations with dim ambient light or when balancing flash with minimal background illumination.