It can be noted here that the only important thing is that the users must ensure that the proper fixing of the angle between the flash beam and the lens axis. The general rule here is that the photographer must keep the angle wide enough that the light beam from the flash does not reflect off the retina of the person being photographed and comes right back into the digital camera lens. A good idea is to make the red-eye reduction work by making the flash shine a light into the eyes of the person being photographed just before the flash is incident and the shutter is pressed. This causes the irises in the eyes of the person being photographed to narrow down or shrink. As a result of this the eye develops a smaller opening for the eye view of the digital camera and does not show off the blood filled retina. This light is called pre light! And very importantly this process works only if the person to be photographed is in point of fact looking directly at the flash for the pre-light to come.
Other factors influencing the red eye are the level of ambient light during the time when the photograph is being taken and how near the flash light is to the lens. The rule of thumb comes out that the brighter the ambient light; the lesser is the effect of red eyes, everything else being one and the same. As the flashlight goes farther from the lens, the fewer becomes the effect of red eyes, everything else being one and the same again. Thus the key idea is that red eye is not caused if the ambient light is comparatively high. And it does have a significant effect if the shooting area is dark. Many digital cameras have built in features for anti red eye that is used to reduce red eye when taking a picture of a person looking straight at the camera also. But manually, the best red eye reduction can be obtained with the help of an external flash as described.
The above discussion has dealt with the most important ideas regarding the red eye effect. The discussion has analyzed the inherent facts about the digital camera red eye effect, their causes as well as remedies. The only thing that remains is that the users must implement these ideas while shooting under circumstances discussed here so that the red eye effect cannot harm the beauties of art created with the aid of the fantastic device, the digital camera!