Flash is a supplemental lighting equipment, it can ensure the footage clear and bright in the dark, outside time, Flash can also be used as an auxiliary source used to emphasize skin tones. Photographers can also request features special effects.
1: change in color temperature.
2: improve the subject lighting conditions
3: reflected light, does not destroy the subject field environment
4: adding catch lights
5: multiple lamp combinations, shaping the image of your subject
6: decrease or increase the contrast
7: Instant stop shooting