Why Use a Flashgun?
Many people with digital SLR cameras want to know why they should use a flashgun. All digital SLR cameras will have built in flashes which can be used to provide light. However, flashguns should be used for a number of different reasons.
Flash guns are separate from your camera. This means that you are able to easily direct them in a different direction to your camera lens. This makes it very simple to diffuse the flash or bounce it off walls or ceilings. This makes it much easier to use your flash.
The built in flashes on most cameras are very weak. These are not bright enough to provide enough light in dark conditions. However, flashguns are much larger. They are much more powerful and provide much more light.
Reduces Red Eye
Red eye problems are exaggerated because the flash is very close to the lens. By using an external flash gun, it is possible to reduce red eye problems.
By using a built in flash, you will consume your camera's batteries to power it. This can use up a lot of power which means you won't be able to shoot for as long. To make this less of an issue, you can use an external flash gun. These are powered by additional batteries which should mean you can shoot for longer.