Understanding Red-Eye in photos and how it can be prevented
Why are eyes red in photos?
Red-eye is a phenomenon that happens only when taking photos using a flash. When taking photos in day light or when in high ambient light scenarios peoples eyes look normal. When taking pictures in low ambient light scenarios using a flash the result many times is redness in the peoples eyes.
The reason for the color red is simple when flash light from the camera hits the eyes it penetrates and is reflected back from the retina. The color of the reflected light is red because the light is actually reflected from the red blood in the retina.
In some scenarios the red-eye is evident while in others it is mild or doesnt seem to appear at all. One of the main factors for that is the state of the pupils. If the pupils are dilated (for example the pupils dilate in darkness or when drinking alcohol) more light is reflected back from the retina and the eyes in the photo appear redder.
Common way to reduce red-eye
The most commonly used method to reduce red-eye is activating the cameras built-in red-eye reduction feature....