Fixing Red Eyes
"Red Eye" is caused by two factors that must both be present:
- The irises of the subject must be dialated, i.e. in a low light setting
- The Flash must be in close proximity to the camera's lens
Because both of these factors must be present, there are different techniques to avoid the red eye effect:
- Constrict the irises of the subject. Manufacturers of small cameras without a hot shoe (for external flash) will choose this approach and accomplish it by "pre" flashing the subject.
- A better approach in my opinion is to move the flash away from the camera by using an external flash and even bouncing the flash off of a wall or ceiling.