Long Exposure

Long-exposure photography or time-exposure photography involves using a long-duration shutter speed to sharply capture the stationary elements of images while blurring, smearing, or obscuring the moving elements. The paths of moving light sources become clearly visible.

When a scene includes both stationary and moving subjects (for example, a fixed street and moving cars or a camera within a car showing a fixed dashboard and moving scenery), a slow shutter speed can cause interesting effects, such as light trails.
Long exposures are easiest to accomplish in low-light conditions, but can be done in brighter light using neutral density filters or specially designed cameras.

Long-exposure photography is often used in a night-time setting in order to produce a near daytime effect in the photo. By leaving the camera’s shutter open for an extended period of time, more light is absorbed, creating a brighter product. If the camera is stationary for the entire period of time that the shutter is open, a very vibrant and clear photograph can be produced.

A 30-second-long exposure sharply captured the still elements of this image while blurring the waterfall into a mist-like appearance. Debris in the swirling water in the pool forms complete circles. Long exposures can blur moving water so it has mist-like qualities while keeping stationary objects like land and structures sharp

Low Key Photography

Low-key lighting is a style of lighting for photography, film or television. It is a necessary element in creating a chiaroscuro effect. Traditional photographic lighting, three-point lighting uses a key light, a fill light, and a back light for illumination. Low-key lighting often uses only one key light, optionally controlled with a fill light or a simple reflector.

Low key light accentuates the contours of an object by throwing areas into shade while a fill light or reflector may illuminate the shadow areas to control contrast. The relative strength of key-to-fill, known as the lighting ratio, can be measured using a light meter. Low key lighting has a higher lighting ratio, e.g. 8:1, than high-key lighting, which can approach 1:1.

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The term “low key” is used in cinematography to refer to any scene with a high lighting ratio, especially if there is a predominance of shadowy areas. It tends to heighten the sense of alienation felt by the viewer, hence is commonly used in film noir and horror genres.