Built-In Flash

The secret of knowing when to use built-in camera flash lies in the ability to analyze the amount of light falling on your subject, and the range of lights to darks within your scene. Sometimes its best not to use flash at all, but instead to use a tripod and slow down your shutter speed, or increase your ISO.

Learning to tell when light is too low for your camera to capture is something you will learn over time, but in the meantime, here are some guidelines to help you out.

Using Built-In Flash Indoors

When to use it:

When the light is low (i.e. your scene is a bit dark) and no tripod is available, and there's no lamp you can turn on to brighten the scene, and you've kicked up your ISO to 400 (even 800) and still your shutter speed is too slow to hand-hold your camera, then flash is the only option available to help your camera properly expose the image!

Warnings:

1) When ISO is too high, noise can appear in your image, so avoid setting ISO above 400 if you can help it.

2) Check your manual for maximum flash distance, and ensure your subject is within that distance from your lens.

3) Enable your camera's red-eye reduction mode, if it has one, when people or animals are your main subject and you are using flash.

Problem #1: Low light, flash is deployed, but resulting photo is less than perfect: overexposed foreground, underexposed background, flat lighting, and/or image is a bit too contrasty.

Solution: Find some ambient light to act as fill light on your subject to minimize harsh shadows caused by your flash. In combination with your flash, the ambient light will increase perceived depth of image by making your subject appear separate from the background. For example, if trying to photograph people in a dimly lit restaurant, try holding a tea-light candle or small lamp below their chins to counteract the shadows caused when your flash fires.

Problem #2: Too much ambient light is present: your subject becomes silhouetted against a bright window.

Solution: Enable your built-in flash to brighten the subject and control the contrast. This use of built-in flash will add dimension to your subject and focus the viewer's attention.

Using Built-In Flash Outdoors

When to use it:

When you're outdoors, and the sun is up, and you're photographing people, always enable your built-in flash! This technique will make your friends pop out of the background, and colours will be saturated.

Warnings:

1) To improve skin tone, meter off the subject's skin directly, using spot metering, or else try to zoom in until your model makes up 75% of the frame.

2) Check out your camera's manual so that you know how to force the flash to fire when ambient light is high; automatic settings for flash often only set off the flash when light is low.

For more information on outdoor use, please see my article about Outdoor Lighting. It discusses use of relfectors and diffusers to improve results with flash and ambient lighting.