Let’s start by agreeing on some terms:

Ambient light: What’s already there at the venue. It could almost none, could be some ugly fluorescents or PAR flood bulbs in the ceiling, could be the sunshine. It might stay the same or it might keep changing, as the sun often does.

Continuous light: a light that is on all the time, one that you bring with you to the event.

1. Incandescent or tungsten lighting: “old fashioned” light bulbs like the ones that Thomas Edison made practical. They’re cheap but they waste much of the energy that goes into them to create heat.

2. 

   Compact Fluorescent Bulbs (CFL)

   CFL – Compact Fluorescent Bulbs. Most fit the same household socket as a tungsten bulb. They burn much cooler than incandescent bulbs. When they break, they pose an environmental hazard.

3. LED bulbs – Light Emitting Diode. These burn cool and are available in many styles. When you get enough of the tiny diodes they can add up to a lot of light! They can come in the form of “ropes” or shaped like convention incandescent bulbs, and also as large arrays.
4. Halogen bulbs. Bright but hot and pricey. When I say hot I mean HOT – they’ll burn you badly.

Electronic Flash (often referred to as “strobe”). A system that stores power in a capacitor and then dumps it into a flash tube very quickly, making great intensity for a very short time. Think of it as “lightning in a glass tube.” That means you can use a high shutter speed on your camera – up to 1/160 or 1/200 on most cameras, and the ambient lighting stops having much affect on your photos.

You still need some continuous lighting coming from approximately the same area as the flash so your subjects can see to pose and so the camera can autofocus. Most studio strobes have a modeling light to fill this function.

Advantages of continuous light:

• You can use it with any kind of a camera – it doesn’t need to be connected to either the camera or the computer.
• It’s relatively cheap
• There are no questions about it: it’s either on or it’s off.

Disadvantages of continuous light:

• You can’t use high shutter speeds to freeze subject motion unless the light is extremely bright or you set your ISO (film speed) really high. So some of the photos of your subjects will probably be blurry, particularly if they’re active
• It doesn’t overpower the ambient light, so you might get shadows or bright areas from a bulb right over your booth or from the sunshine.
• Your guests won’t really know when the photo is taken

Almost all cameras have a built-in, pop-up flash

Using the camera’s built-in flash, the advantages

• Almost all point and shoot or DSLR cameras have a built-in flash
• The connections are built-in so you need no cords
• The high effective shutter speed freezes action so your subjects aren’t blurred.

Worries about the built-in flash

• It’s small and close to the lens, so the lighting is kind of harsh
• The recycling time for the flash sets an absolute minimum for the time between shots.
• If you’re shooting on battery power that recycle time gets longer and longer until you run out of juice.
• I suspect (don’t have any reliable statistics) that built-in flash units won’t last long in the intensive use they get in a photo booth.
• Built-in flash units are not very powerful.
• You’ll still need a separate modeling light.

Alien Bee monolight studio strobe

Advantages of a separate flash (strobe):

• It’s really bright for a short period of time – usually less than 1/500th of a second.
• Its light is about the same color as daylight, and it’s consistent.
• If your camera is set to a high shutter speed the flash will overpower ambient light, so you get fewer shadows and hot spots.
• The short duration of the flash has the effect of a very high shutter speed – it freezes action so your subjects aren’t blurred.
• You and your subjects can tell each time the camera fires.

Disadvantages of separate flash:

• It’s a pain in the neck to hook it up to a camera.
• Some cameras (webcams) don’t have a way to connect a flash at all.
• Good flash guns are bulky.
• Flash units need power, and AC power is best if the flash is going to be used a lot (such as in a photo booth.)

(This is part 1 of 3 segments on lighting for the photo booth)

Blog contributor Chris Lydle is author of The Photobooth Book