Exposure is the process of controlling the amount of light that reaches the camera's sensor. This is done by adjusting the aperture, shutter speed, and ISO.

Exposure is affected by three main factors: aperture, shutter speed, and ISO. Aperture controls the size of the opening in the lens, shutter speed controls the length of time that the shutter is open, and ISO controls the sensitivity of the camera's sensor to light.

A larger aperture (smaller f-number) allows more light to pass through the lens, resulting in a brighter image. Conversely, a smaller aperture (larger f-number) allows less light to pass through the lens, resulting in a darker image.

A slower shutter speed allows more time for light to reach the camera's sensor, resulting in a brighter image. Conversely, a faster shutter speed allows less time for light to reach the sensor, resulting in a darker image.

A higher ISO increases the sensitivity of the camera's sensor to light, resulting in a brighter image. Conversely, a lower ISO decreases the sensitivity of the sensor, resulting in a darker image.

The exposure triangle is a concept that describes the relationship between aperture, shutter speed, and ISO. These three factors work together to control the amount of light that reaches the camera's sensor.

Underexposure occurs when the camera's sensor receives too little light, resulting in a dark image. Overexposure occurs when the sensor receives too much light, resulting in a bright image.

A light meter is the most accurate way to measure the amount of light in a scene and determine the correct exposure. The camera's built-in exposure meter can also be used, but it is not as accurate as a light meter.

Natural light is the light that comes from the sun, while artificial light is the light that comes from man-made sources, such as lamps, flashlights, and candles.

There are two main types of artificial light: continuous light and strobe light. Continuous light is a constant source of light, while strobe light is a pulsed source of light.

Continuous light is easier to control, more consistent, and less expensive than strobe light.

Strobe light can freeze motion, create dramatic effects, and is more portable than continuous light.

The best way to use natural light in photography is to shoot during the golden hours (the hour after sunrise and the hour before sunset), use a reflector to bounce light back into the scene, and use a diffuser to soften the light.

The best way to use artificial light in photography is to use a softbox to diffuse the light, use a snoot to focus the light, and use a grid to control the direction of the light.

Backlighting, sidelighting, and frontlighting are all common lighting techniques in photography. Backlighting is when the light source is behind the subject, sidelighting is when the light source is to the side of the subject, and frontlighting is when the light source is in front of the subject.