1. Key Light The main light in a studio lighting set-up. This light is often the closest to your subject and the most dominant light in your composition.
2. Fill Light The fill light is the second most important light in that it fills in the shadow areas in your portrait. The fill light is usually a reflector that bounces into an umbrella and sits on the opposite side of the key light. The fill light sits farther away from your subject, and is not as bright of a light as the key light.
3. Background Light The background light usually sits behind the model and reflects light onto the background sweep. The background light is necessary to separate the model from the backdrop especially if the sweep matches your models hair tone.
4. Rim/Hair Light The rim or hair light is an extra added light that usually sits above the models’ head. It often produces a soft illumination on the hair (halo effect) that helps define in more detail the hair on the model, and further separates the model from the background.
5. Reflectors/Scoop The slang term for a reflector light is termed “scoop.” The reflector lights provide the overall main lighting of your portrait. The reflector lights can be partially covered, diffused or bounced into umbrellas or white cards to produce different lighting effects. The term “Reflector” can also mean a white, silver, or gold disc or card that acts to bounce light into your composition.
6. Diffuser A diffuser is any material or technique that softens a bright light. Direct light from most light sources are often very harsh on a subjects face. Diffusing your light produces better skin tones and softens the lines and wrinkles on a face. Common Diffusers are soft boxes, or portable discs made out of a semi- transparent material.
7. Bounce Light that bounces off of any surface and back into your portrait composition is referred to as a bounce light. Simple bounce lighting is produced with a small or large white card that is placed on the opposite side of your key or fill light. Bounce light can also be produced by pointing a reflector directly into a wall or off a ceiling.
8. Umbrella An umbrella is the most common way lights are diffused in a portrait. They are cheaper than soft boxes and can be moved very easily in different locations on your set.
9. Sweep The sweep is almost the same term as a background or background drop cloth. A sweep is usually pulled down to the floor and extends under the feet of the model, thus, sweeping under the feet of the model. It is used in full body (head to toe) shots.
10. Soft Box A soft box is a lightweight box that sits on the front of a light source. It is usually made out a fire retardant material and has a acetate material on the front that diffuses soft light onto a subject. Soft boxes come in many different sizes and shapes and are used in most professional commercial and fashion studios.
11. Rembrandt Lighting Rembrandt Lighting is the common term used for a lighting set up that uses only one light source. It is the simplest form of light. The results are often dramatic and moody.
12. Classic Three Point-Lighting A lighting set up that consists of a key light, fill light, and backlight. It the most classic and most basic lighting set up in a studio. Photographers often start with three-point lighting set ups and add their own extras during a photo shoot.
13. Four-Point Lighting Four point lighting is very much the same as three-point lighting in that the set up contains a key light, fill light, and background light, but it also includes a hair or rim light.
14. High Key Lighting High key lighting is a term often used to describe a lighting set up that uses a stark white background and four-point lighting. It produces a shot that shows fine details, with soft flattering light (not too much contrast). It is often used in fashion photography, so that designers can see the most detail in the clothing, as well as, the flattering effect the soft light has on the skin of the model.
15. Light ratio The light ratio is how you control the lighting effect in your portrait lighting set up. This means the ratio of the highlights to the shadow areas in your shot. For Example: If your highlights are four stops greater than your shadows, you will produce an image with lots of contrast. If your highlight to shadow ratio is only one stop difference, you will produce an image that is very low in contrast (flatter).