Red Eye

By  Ron Hart

On looking over some of the “kid” photos taken recently in our family, I see lots of red eye. Red eye is caused by light reflected back from the retina (where there are blood vessels) because the iris is open for the ambient light and does not have time to adjust for the high intensity of the flash.

With patience and the proper software, red eye can be eliminated, but it is better to prevent it. Telling children to “look at the camera” and taking a flash picture, just about guaranties severe red eye.

Many flashes have a so-called red eye reduction mode (note it’s a reduction, not elimination). This method usually sends out one or more low intensity flash pulses intended to close the iris, followed by a high intensity flash. In theory it works. Usually the subject becomes annoyed at all the flashes however, and closes their eyes, or turns their head, or worse.

Here are some ways to prevent or at least reduce red eye:

• Move the flash off camera—this is impossible on most modern point and shoot and digital cameras.
• Turn on room lights to close the pupils of the subjects.
• Have the subject look off camera. Don’t have the subject look directly at the camera.