When an external strobe is used, the image acquires greater brilliance as an abundance of light is shed and it reaches further than the built-in flash, particularly when the subject is further away. Colors like red and orange are absorbed underwater, so the deeper you go, the more prevalent blue becomes. This is why an external strobe, a high-power artificial light, is used to bring out the inherent colors of the underwater objects. Since the built-in flash does not have a strong intensity, the light is unable to reach objects that are further away. Using the external strobe at an angle is an effective means of preventing floating particles - called backscatter from reflecting light in your picture. These packages include the camera, housing, strobe(s) & accessories needed for true underwater digital photography.