Choosing a Flash Unit
If you want to get serious about your photography, invest in a dedicated flash unit and take control of the light.
The purposeful manipulation of light - how much of it, what direction it takes and suchlike - is one of the most creative elements in any photographer's toolbox.
If you're into portraiture or macro photography then a flashgun is an essential accessory, and something that will even prove useful when you're shooting outdoors in daylight, and fill-in flash is required.Used skilfully, a flashgun can also be used to highlight anything from model's perfect cheekbones to the patterns on a butterfly's wings. While most DSLRs feature a built-in, pop-up flash that's capable of producing perfectly adequate results when used in close proximity, a dedicated flashgun unit will give you much more creative freedom over how you want to light your subject.
Dedicated flash units come in a variety of shapes and sizes that lend themselves to different genres of photography. The trick is to decide what kind of flash best suits your own photographic needs and to ensure that the one you have your heart set on is compatible with your camera.
Most of the major camera manufacturers produce their own flashes, but there are also several independent manufacturers, such as Metz and Sigma, that produce their own flashguns. When looking at models from these manufacturers be sure to check they are compatible with your camera system.
Camera-Top The most popular option for general purpose photography, these connect to the top of your camera via the hotshue directly above the viewfinder. Once attached most operate automatically with your camera's TTL system, although more advanced models also allow manual operation for added creativity. | Ringflash Invented in the 1950s to assist with dental photography, the ringflash design has since found favor with macro and fashion enthusiasts as it provides an even concentration of light around the lens and eliminates shadows.Most ringflash units attach directly to, or around, your lens, and are connected to the hotshue via a cable. |
Twinflash Working on a similar design principle to ringflashes, twinflashes are favored by macro photographers as the twin heads highlight the subject while canceling each others shadow out. Other units can also be added, and there is often scope to move the units around the lens. | Hammerhead Favored by wedding and press photographers thanks to their powerful output, hammerhead flashguns generally sit on brackets that screw into the camera's tripod bushing. The flash unit itself sits to the side of the camera's body, providing a helpful off-center angle that's also less prone to red-eye. |
Need to KnowFlash jargon explained | |
| GD - Guide Number indicates flash power (how far it will reach at a certain aperture and ISO). The higher the figure, the more powerful. If you divide the number by the shooting distance (in metres) you will get your working apperture (or, divide it by your aperture to get your shooting distance). | AF Assist - The flash can supplement the camera's own illumination to provide more accurate autofocus at longer distances and when shooting in lower light or difficult lighting conditions. |
| TTL - Stands for "Through The Lens" flash metering. TTL technology matches the flash power with the info from the camera's sensor for correct exposure. | Diffuser - A diffusion device built into the flash to increase the spread of the output to cover the wider area covered by wideangle lenses. |
| Wireless Slave Compatibility - This lets the flash control one or more off-camera units, or slaves, sharing selected shooting data for a coherently managed portable lighting set-up without the need for wires. | Zoom head - Concentrates the energy of your flash when using telephoto lenses. Motorized zooms automatically alter the coverage of the flash output to match the focal length of your lens. |
| Swivel and Tilt - Some units have heads that swivel sideways and tilt up, allowing you to bounce the light off a ceiling or wall to give a softer light. | PF Sync - Focal Plane, or PF, sync mode allows flash photography at any shutter speed. It does so by using a rapid pulse of light instead of a single burst, in order to illuminate the scene as the shutter travels across the sensor plane. |
