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Disclaimer: The current photo displayed here is not mine and is not being used for profit and is being displayed for educational use only. No infringement is intended nor implied. The camera is on its side (portrait orientation). One on-camera flash with a black "flag" (craft foam or construction paper). The flash head is angled between 45 to 65 degrees, or to give the best bounce of light off of the ceiling without the light hitting the subject directly. The three white backdrops have been arranged to represent a white walled hallway. I've added the pencil sketch that I based this lighting diagram on. There is also an image of the flash with the black "flag" to help illustrate what I'm talking about. A flash can only generate a finite amount of light. If the resulting image is too dark, first try opening the aperture (making the f-number smaller, this will also decrease the depth-of-field), second try increasing the ISO setting, this will make the DSLR sensor more sensitive to light, but will increase digital noise in the image.