Red-eye" phenomenon is a night scene or indoor flash shooting characters, due to the subject of the under-eye blood vessels reflecting the impact of the photographs of the characters on the pupil of the red, the characters look like the eyes of the eyes of rabbits. The main reason for the formation of red eye is in a darker environment, the pupil of the human eye will take the initiative to dilate to adapt to the needs of the observation environment, at this time, such as flash and camera lens optical axis is relatively close to the flash, the flash's strong light will be reflected through the human fundus of the lens, due to the human fundus of the eye has a wealth of capillary blood vessels, these blood vessels are brightly lit by the formation of the red spot, the formation of red eye. To prevent the phenomenon of "red-eye" can be used in a variety of ways:
1. Increase the distance between the flash and the optical axis of the lens. The greater the distance between the two, the less likely to appear "red-eye", such as portable digital cameras using in-camera flash shooting is prone to red-eye, and digital SLR cameras plus independent flash shooting is not easy to red-eye.
2. Utilize the flash anti-red-eye function. Now the general digital camera (including the more advanced external electronic flash) have anti-red-eye function, as long as the shooting character pre-set to anti-red-eye function can be. The camera will be issued before the official flash to do several pre-flash, through the pre-flash, so that the pupil of the human eye to narrow, thereby reducing the phenomenon of red-eye. However, this is a power hungry camera and should be used with caution on important shooting occasions where battery life is limited.
3. Let the subject look at the brighter object. It's good to let your subject look at brighter objects when you're shooting people, even if you don't use a flash, so you can add a spot of light in the subject's eyes and make them look more energized. And in a darker environment using flash photography, such as characters looking at the brighter lights of the window can make the pupil narrowing, to avoid red-eye.
4. Post software elimination. If you find the subject after shooting red-eye need not worry, you can use special software to modify the eyes, can be in Photoshop with the help of the toolbar on the "gun" to change the color, you can also use the "copy the stamp" to modify, also You can copy the black eye to cover the red eye and so on, as long as the patient and careful operation, you can do seamless.