Red eye is a common problem for all fresh photographers, here we are about to figure it out what may cause red eye in our images.
Just as the name implies, red eye means the eye in the image in which we take at night turns red. Eyes of the person appear to be red in the pupil, yeah, just like a vampire. Scary, hmm? However we are not shooting horror films, we don’t want it anyway. There are probably thousands of family versions with red eye in the photos. The common reason for this is that the light reflected off blood vessels in the back of the eye.
How is it formed
It’s easy to understand that light reflects off the surface of objects so the camera can “see” the object as we do. When light source is almost equal to the level of the eye and it reflects at an angle equal and opposite to its entry, most commonly the pupil of the eye is dilated and gives more room for light to enter and exit the eye, red eye occurs.
Conditions for red eye
Usually occurs when meets all these conditions like, built-in camera flash, pupils dilated and camera is almost at same level with the eye.
How to prevent
It is not difficult as you might think. To prevent red eye you only need to change the angle that light gets in and out from the eye or the harshness of the light. There are ways to realize this, e.g. to use a flash with a tilt head or a reflector to add light or a diffuser on the flash to soft the light, shoot from a slightly lower or higher level than the eyes of your subjects.
Even if it’s generated, we got software to eliminate it. As I know there is integrated function for red eye in Photoshop. But it’s best to avoid it in the first place, nature always means better.