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Camera flashes are well-known for indiscretion and creating demonic red-eye effects, but they can actually prove to be one of the most valuable allies for any photographer. The trick is to understand their limitations and the various options your camera has to offer.

The range of a typical popup flash is just a few metres, beyond which it will have no effect whatsoever. There's therefore no point using a flash at a concert unless you're in the front row, and no point using it to illuminate distant buildings at night.

The trouble is that most cameras set to automatic judge only light, not distance. They see a dark view and believe the flash is the best way to illuminate it. Unfortunately, if the subject is more than a few metres away, the flash will have no effect at all. Worse, because the camera expected the flash to illuminate the subject, the picture will be woefully underexposed.

The first trick is learning how to switch your flash off. Most cameras control their flash options using a button labelled with a lightning bolt. To switch the flash off, just press it until you see the lightning symbol with a circle round it and a line through it. With the flash off, your camera will have to make the most of the available light and adjust the exposure to compensate. Note that longer exposures may require a tripod or a steady spot for the camera to avoid shake.

The next trick with your flash is forcing it to go off when your camera thinks it's not required. If you're taking a photo of someone under dimmer conditions or with a very bright background, the person can often look a bit dark. So long as they're within a few metres, though, your flash can provide a boost. This is known as a fill-in flash. Again, you press the flash button until the lightning symbol is always there, which means it will go off every time.

Taking this concept a step further is the slow-synchro option. This combines the flash with a longer exposure both to illuminate a person in the foreground and capture lights in the background. It's ideal for photographing people against a city skyline at night.

More sophisticated cameras offer an additional 'rear curtain' option. This fires the flash at the end of a long exposure rather than the beginning. This allows you to use a long exposure to trail moving lights, then have the flash freeze the subject at the end. It's particularly effective when photographing children twirling sparklers on Bonfire Night.

Finally, we can't talk about flashes without discussing red-eye, where flash-light is reflected back from the retina. Red-eye reduction modes help by firing the flash several times in an attempt to reduce the pupil's size, but for better results you'll need to use brighter conditions, an external flash gun or software to remove it later.

	1 Force your flash to fire when photographing people in dim conditions.

	2 For great sparkler photos, combine a long exposure with a rear-curtain flash.

	3 Flashes are great for freezing fast action such as exploding water balloons.