Studio lighting usually refers to lights designed especially for photography. These lights are used in conjunction various light “modifiers” (so called because they all modify the quality of the light in different ways. These lights are designed to be mounted on booms or stands, and are able to allow attachments to be easily mounted.
If you are looking to buy a studio lighting kit, there are a few common packages around. For home or semi-pro use, a basic kit will either come with one light or two, with light stands for each, and should include reflectors for each light, an umbrella and a softbox at minimum. These modifiers are broadly useful and will allow you to shoot almost anything.
Modifiers
Reflectors are simply a short metal cone shape, that clip or screw onto the business end of the strobe. They produce a fairly hard, directional light with a sharp shadow.
Umbrellas soften the light considerably compared to a bare bulb or reflector. The wide area of the umbrella reflects light back from the bulb, helping to fill in shadows cast by the main light on an object. Photographic umbrellas come in white or silver to give further choice in light quality, with silver producing a slightly ‘sparkly’ or specular look compared to the more even fill of a white backing. Some umbrellas also come with a backing that can be removed so that the umbrella can be reversed and mounted in front of the light, producing a more diffuse light similar to a softbox. Lowel.com have a good comparison of the effects of an umbrella used in different ways.
A softbox is a collapsible structure with reflective interior, and an opaque covering. These produce the softest light of all the modifiers because they effectively increase the size of the area emitting light, allowing the light to wrap further around the subject of the photograph.
Another consideration is whether to shell out extra for a portable light. Battery packs are available that let strobes be used on location, and the flexibility of these can allow for real creativity.
Studio lights can be divided into two main categories – strobe, or continuous.
Studio strobes work like over-sized on-camera flash units, firing a very brief burst of light when you take a picture. Unlike smaller flash units, these usually have a “modeling light” which is always on, and gives a preview of how the light will look when the strobe fires. Good quality units will have modeling lights that vary in strength in proportion to the strength of the actual flash burst. Strobes are most useful for shooting moving things, like people. The strength of a strobe is measured in watt seconds, with a wide range available. Although it is tempting to go for the strongest you can afford, in reality it is better not to go overboard unless you have a particular purpose in mind that will require a LOT of power. The problem with a studio strobe that is too powerful is that sometimes you will want to work with a larger aperture to achieve a particular effect. Although you can adjust the power of the strobe, on a large unit even the lowest power will be too high to allow shooting at a very wide aperture (this is because of the upper limit of shutter speed that can be used when shooting flash, called the flash-sync speed).
Continuous lights are always on, as the name suggests. These are often halogen bulbs, designed to produce lots of light all the time instead of in a burst. The drawback to this type of light is that they can produce a lot of heat (in fact they are also called hotlights by some photographers), and also be expensive to run for long periods compared to the burst of a strobe. However for product shots where all movement can be controlled, these can be very useful giving a true preview of the effect of the light in advance and taking the guesswork out of moving your lights around and changing modifiers. These lights can also be much cheaper than strobes, and a basic continuous studio lighting kit of hot lights, stands and an umbrella or two isn’t a bad way to learn about lighting on a budget.
Studio lighting can be difficult to master, but immensely useful – and learning is more than half the fun!