All cameras have built in flash nowadays. The point and shoot has one and the digital SLR has one too. It is often used during the night or whenever there isn’t enough light to achieve a proper exposure. However, despite having built in flashes, camera manufacturers are still selling external flashes. They are priced at around $300 to $500 which can already get you a second DSLR. Here are a couple of reasons to buy an external flash.
An external flash has more power. You’ll notice that when using your camera’s built in flash the exposure is still under despite using the proper settings. This often happens when the subject is far from the camera. The built in flash just can’t throw light at that distance so an external one is needed.
The Guide Number (GN) shows how powerful a flash is. For example, Canon’s 580EXII has a GN of 190′ (58 m)(ISO 100 at 105mm) while the built in flash has 42′ (13m). With this amount of power, you can take shots that were impossible with a built flash.
Another thing to consider is the flash’s recycling time. With a built in flash, you can’t shoot to your heart’s content since it has to maintain its temperature to avoid overheating. With an external flash, you can shoot up to 8fps without breaking a sweat. This is very important in shooting events where every moment counts.
Most photographers won’t use flash when there is a lot of light. But when there’s a lot of light it can result into harsh lighting which is not pleasing to the eye. To remedy this, we use fill flash. The built in flash can do fire a fill flash too but since it’s lacking power, you won’t be able to use it when you really need to. For example, noon time and there’s no shade nearby. Without fill flash there will be harsh shadows all over. The fill flash will soften the shadows which will yield to a better looking picture.
An external flash head can be aimed at various positions. This means that you can bounce the light to almost everywhere. This means that when used indoors, you can aim your flash on the ceiling and the light from the ceiling will act like a huge softbox. This will produce softer shadows compared to directly aiming the flash at the subjects.
You can also aim at your left or at your back. The possibilities are endless and limited only by your creativity.
Out of Camera
You can use your external flash out of your camera. Photographers who use this technique are called strobists. Think of your external flash as a studio light but with greater portability but less power. You can attach light modifiers to your flash much like studio lights. Umbrellas, softboxes, grids, and snoots are just some of the accessories you can attach to your speedlight.
Acquiring an external flash can be daunting because of its price. However, once you realize and accept the potential of this purchase I can assure you that your money will be well spent. Photographers in various forums always suggest in getting a flash first instead of an expensive lens. An expensive lens can give you great shots but an external flash can give you more than that.