This article will focus on the type of flash reflection that occurs when an object is directly on or extremely close to the camera’s lens. It is not referring to the flash reflections commonly seen in photos where mirrors or other reflective surfaces are in view.
When any object is directly on, or extremely close to the camera lens as the flash fires, the flash can illuminate the object (or not) in odd, unexpected ways.
Please look at the 3 photos posted with this article. These photos were taken during the day, indoors. Natural light was the only light source in the room, other than the camera’s flash. I had the blinds closed to insure it was dark enough that the flash would fire. The camera I used was a compact point ‘n shoot, Canon PowerShot ELPH300 HS, 12.1 MP. The photos were taken in full auto mode.
Photo #1: The object is directly on (touching) the camera lens. Notice how the background is well lit and in focus, but the subject is very dark. When an object is on the camera’s lens, the camera cannot focus on it. In auto focus mode, since the camera could not focus on the object, it focused on the background, and metered accordingly. The result was a dark shadow effect on the object. This will happen no matter the color of the object. We commonly see this effect when there is an insect or piece of debris on the lens of the camera.
Photo #2: The object is just slightly away from the lens, within ½ inch. At this range, the camera still could not focus on the object very well, so again the camera focused on the background, and metered accordingly. At this distance though, the object is in the “orb zone” or range where the flash will bounce off the object. When this happens, the flash is reflected back into the camera lens, and the result is a washed out effect on the object. In some circumstances, the flash reflection can wash out the entire photo, giving it a cloudy or foggy appearance. We commonly see this effect when someone takes a photo, not realizing their finger, or a camera strap, or some other object was near the camera lens. This would be the same as taking a light and shining it into your eyes.
Photo #3: The object is sufficiently away from the camera and out of the “orb zone”. The flash does not reflect off of the object and back into the lens. At this distance the camera was able to focus on the object, and metered on the object. Notice now how the background has become dark and out of focus. These results and their severity will vary from camera to camera, but all cameras, especially compacts and cell phones, are susceptible to this effect.