Reducing Red Eye
What is Red Eye? Red eye is a problem that shows up in portrait shots and also often in photos of pets and other animals. The centre of the eye becomes bright red. Other colours can also appear, with the most common second colour being green.
Why does it appear in so many pictures?
Red eye is caused by the light from the camera's flash unit reflecting back to the camera's lens. The light is reflected back by a part of the eye known as the retina. This acts as a mirror to the light and shines it straight back at the camera.
The problem is accentuated by the close proximity of the lens and flash unit on so many consumer level digital cameras. This leads to the angle the light reflects back at being very small. This means it is likely to score a direct hit on the lens. This is a downside of the desire for people to own very small cameras. Owing to the small size it is impossible to get any real distance between the lens and flash unit.
The larger the pupils of the person you are taking a picture of the more likely you are to suffer from red eye. As people relax their pupils dilate and become bigger. This is why so many party pictures are blighted with the problem as people are more relaxed in this type of environment, especially when the have had a couple of drinks.
Buying a digital camera to eliminate red eye
If you check through my indoor portrait test shots (Indoor portrait test shots) it is noticeable one type of digital camera routinely performs better than any other in this area. These are the cameras with pop up flash units. This helps to distance the flash unit from the lens and increase the angle the light is reflected back at. The problem is this type of camera tends to be considerably larger than standard sized digital cameras and also more expensive too.
The ideal set up is to buy a digital camera that can use an external flash unit. The light from these units can be bounced off the ceiling or wall so that the angle the light bounces back at is changed completely. This more or less eliminates the possibility of red eye spoiling a photo. Again the problem is the cost of buying this type of camera and the additional flashgun. The vast majority of small digital cameras cannot use any type if external flash light.
Even with a standard consumer digital camera there are features you can look out for to try and eliminate or at least reduce the problem. The majority of digital cameras now come with a red eye reduction flash mode. This works by firing the flash unit twice. First there is a small burst of flash. It is this burst whose job it is to hit the pupil and make it contract before the main burst of flash lights the picture. With the pupil now smaller the amount of light reflected back to the camera's lens from the main burst of flash is much reduced.
The downside of using red eye reduction is it delays the shot. As the picture is not taken until the first burst of light has had a chance to work. This can lead to you missing the best shot, especially when young children are involved. The extra burst of flash also has an impact on battery life. Therefore it is recommended that you only use this setting when you really need to.
A relatively new feature is Red Eye Fix. At the time of writing this is not widely available. This is a piece of software built into the camera. You use it for any photos you have already taken. The idea of the software is that it can identify areas of red eye and replace them with the natural eye colour. I have tested this feature on a few cameras with mixed results. From time to time it is unable to improve the problem and also blackens any corners of the eye that have shown up as red.
Reducing red eye through picture set up
As the two main factors causing this problem are the small angle light is reflected back to the lens and the size of the pupils these are the two main areas to work on.
The first action to take is to try moving closer to the subject. By moving closer you automatically increase the angle the light is sent back at. This helps to avoid it hitting the lens. The next action to take is to ask your subject not to look directly at the lens. You are slightly limited here as the portrait will look strange if the subject is merrily looking off into the distance. Try getting them to look at your shoulder.
To constrict the size of the pupils try to make sure the location you are working in has as much light as possible. Not only will this help to reduce red eye, but it will also help the camera to focus properly.
If you can position yourself in a well lit area so that as the subject looks at you their pupils are naturally constricted by the light.
You can also shine a light into the eyes of the subject just before the photo is taken. This is not the most comfortable of actions for your subject. Therefore for me this is a last resort.
In addition you can also look at ways of reducing the power of the flash unit. This is not always appropriate as you may need full power to light the subject correctly. Many digital cameras offer you a feature allowing you to reduce the power of the flash. Try experimenting with this.
If your camera does not offer this feature then you can also try diffusing the light by covering the flash unit with a thin piece of tissue paper or a cigarette paper. Make sure the paper does not actually touch the unit. This is because if it is hot the paper may stick to it.
Reducing red eye on a PC
In a similar way to the red eye fix software in some digital cameras you can also use software on your PC to try and eradicate the problem. This software is usually more advanced than what you will find in camera and you will have more control over the areas of the eye you would like to be corrected.
Software applications you can try include the Picassa (available for nothing), Adobe Photoshop (and Photoshop Elements) and Paint Shop Pro.
Its never too late!
If you have a set of prints back from development and they are ruined by red eye you can buy a special pen from your local art or camera shop that can reduce the problem.
So there you have it. There are quite a few points to consider and work on. No matter what you do if you are using a small digital camera with the lens close to the flash unit you are likely to suffer from red eye in your photos from time to time. It is the price to pay for the ease and convenience of such small cameras.
Digital Camera Red Eye