When starting out with photography, it’s easy to think that your camera’s flash is only needed indoors or in the dark. But on the contrary, a flash can be very useful in bright shooting conditions.

Also known as using a “fill-in” flash, the idea is that available light (whether natural or artificial) may not always light up your subjects properly. Either that, or the contrast between your subjects and their backgrounds may be too strong. To remedy this, simply use your camera’s built-in flash (or add-on flash unit) to balance out the lighting.

Here are a couple of pictures to better illustrate this:

In the first picture, you’ll see that the lantern looks fine but the street in the background is blown out. This is because the lantern is in the shade and needs more light to be properly exposed.

To solve this problem, a fill-in flash is used to illuminate the lantern (second picture). This reduces the difference in brightness between the foreground and background, allowing you to capture details in both.

Why this works:
In the 2nd shot, the camera’s shutter and aperture are adjusted for the background (which is brighter) while the flash lights up the lantern (which is darker). This works because flashguns have a limited range and weaken with increased distance. This is why the background isn’t blown out by the flash. In contrast, the lantern was lit properly is because I was standing close enough to it.

The proper exposure is handled automatically by most modern cameras, so don’t worry - just enable your flash and it’ll sort itself out.
Why this is necessary:
Like film, the sensors in digital cameras have limited dynamic range. That is, they cannot capture as much contrast as the human eye. Techniques such as this reduce the difference in brightness so that the picture appears more like how the human eye would see it in real life.

Additional information:
There are some issues abut using a flash - some of which are probably more suited to an advanced article about flashes and lighting (i.e. Sync speeds, ISO settings, the effects of varying aperture). When I find time, I’ll write about these.

Do take note that using a flash excessively will drain your camera’s batteries faster (especially if you’re using a compact digicam).
Conclusion:
If you find your subjects too dark or your backgrounds too bright, try using a flash - it helps!