External Camera Flashes

You have the camera,  the lens, the filters... Something's missing. The flash!  Suppose you want to take pictures in a low-lit room, or you are doing a portrait shot and want to fill out the light so that the subject doesn't looked washed out or have red-eye. Or maybe you just want to soften a shot outdoors. You need an external flash for all of these things. External flashes are also known as strobes  or flashguns. 

Flash Types
Shoe-Mount	Handle-Mount	Ring Light	Strobe

There are two main types of external flash units that can be connected to the camera itself via its "hotshoe" (the metal bracket on the top of your camera): a Shoe-Mount Flash  and a Handle-Mounted Flash.  There is also a ring light flash  that connects around the lens and is used for macro photography especially. Lastly, there is the strobe  version.

What Is GN?

Guide numbers, better known as GN, are the units used to measure the power of a flash (usually 100-200 give or take). For an in-depth article concerning GN calculations, see Understanding Guide Numbers.

When Buying Look For...

• Compatible trigger voltage: if it is too high it will damage your camera.
• Autoexposure, Thyristor Control, & Shutter speed auto-settings: in automatic flash units this is what corrects flash metering.
• Zoom: necessary for controlling light levels when using a zoom lens.
• Flash: ready light.
• Bounce capability: a flash unit with a base that can swivel or twist.
• Autofocus units for AF cameras. 

Here Are Some Brands to Consider (C-Net)

• Vivitar 2800 $70
• Vivitar 285 HV $160
• Sunpak 433D TTL $180
• Canon Speedlite 420 EX $300
• Canon Speedlite 540 EZ $480
• Metz 45CL $660

Related Products

• Light Meters 
• Batteries
• Camera Lenses
• Camera Lens Filters
• Tripods 
• Camera Cases 

Additional Links

• About.com - An article on flash basics.
• Electronic Flash Info - On flashes, synchronization, GN and more.
• Howstuffworks.com - Learn how a flash works.