External Flash

Avoid red-eye by keeping the flash away from the lens

Most compact cameras have a flash bulb that is built into the body of the camera. Some are placed on the front of the camera and others sit on top. Most digital SLRs (and a few compact cameras) have a connector where you can attach a larger flash to the camera.

The Problem of Red-Eye

You’ve probably seen red-eye at some point in your photographs of people. Glowing red eyes do not create very flattering portraits. Red eye occurs because the flash is too close to the camera lens. The farther away the flash is from the lens, the less chance you’ll get red eye in your photographs of people.

Many cameras today feature a red eye reduction feature. This feature causes the flash to emit a burst of light before the photograph is taken, which causes the pupils of your subject to narrow. This reduces the chance that you’ll see a lot of red eye in your photograph, although it will not eliminate it completely.

The problem has to do with the angle of the flash relative to the location of the lens.

Angle of Flash Relative to Lens

  • The top section of the illustration shows how a compact camera flash works. The flash is close to the lens, so the light from it bounces right off the retina and back to the camera. This produces a lot of red-eye.
  • The bottom section shows what happens when the flash is moved above and away from the lens. There is a wider angle between the flash and the image captured by the lens. This wide angle results in less direct light being reflected from the eyes.
angle of flash

External Flash and Hot Shoes

To get your flash far away from your camera lens, you need to purchase an external flash, and you need a camera with a hot shoe. A hot shoe is just an open connection on top of the camera where you can attach the external flash. The flash connects to the hot shoe so that it activates when you press the shutter on the camera.

Photographic Example

The item on the left is the external flash unit. If you look closely at the bottom you will see some pins sticking out of it.

On the right is a view looking down at the top of a digital SLR so that you can see the hot shoe. Notice the metal circles on the hot shoe.

The pins on the external flash connect with the metal circles on the hot shoe so when you press the shutter, the external flash goes off.
external flash and hot shoe

Other Uses For Flash

Having an external flash will definitely reduce the amount of red eye that you see in your portraits. But this is not the only reason to purchase an external flash. An external flash gives you greater flexibility when taking photos indoors.

Many of today’s external flashes come with swivel heads. Basically, you can point the flash in any direction: left, right, even up toward the ceiling. This creates a much more natural looking photograph indoors. Rather than blasting your subject with direct light, you can bounce the light off a ceiling or a wall and create some very interesting effects.

Flash can also be useful outdoors on a very sunny day. If the person that you are taking a photo of is wearing a hat, his or her eyes can be lost in shadow. If you use your flash (even though there is plenty of light from the sun) you can reduce the shadows under the hat so that you can see your subject’s eyes.

Do I Really Need an External Flash?

If you think that you will be taking a lot of photos indoors, or a lot of portraits, then consider getting a camera that features a hot shoe. This does not force you to use an external flash — every camera that has a hot shoe also comes with a standard built-in flash. This will simply offer you the versatility in the future if you decide that you’d like more creative options when using your camera’s flash.

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