Shutter speed can have a dramatic impact on the appearance of moving objects. Changes in background blurring are apparent from the need to adjust the aperture size to achieve proper exposure.

The shutter speed dial of a Fujica STX-1.

Slow shutter speed combined with panning the camera can achieve a motion blur for moving objects.

A photo of sparks coming from coals (exposure time 15 seconds)

A photo of dark street at night (exposure time 20 seconds)

An extended exposure can also allow photographers to catch brief flashes of light, as seen here. Exposure time 15 seconds.

In photography, shutter speed is the length of time a shutter is open; the total exposure is proportional to this exposure time, or duration of light reaching the film or image sensor. Photography (fә'tɒgrәfi or fә'tɑːgrәfi (from Greek φωτο and γραφία is the process and Art of recording pictures by means of capturing In Photography, a shutter is a device that allows light to pass for a determined period of time for the purpose of exposing Photographic film or a light-sensitive In Photography, exposure is the total amount of Light allowed to fall on the photographic medium ( Photographic film or Image sensor) during the Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 This article is mainly concerned with Still photography film For Motion picture film please see Film stock. An image sensor is a device that converts an optical image to an electric signal

Introduction

Factors that affect the total exposure of a photograph include the scene luminance, the aperture size (f-number), and the exposure time (shutter speed); photographers can trade off shutter speed and aperture by using units of stops. In Photography, exposure is the total amount of Light allowed to fall on the photographic medium ( Photographic film or Image sensor) during the Luminance is a photometric measure of the density of Luminous intensity in a given direction A stop up and down on each will halve or double the amount of light regulated by each; exposures of equal exposure value can be easily calculated and selected. In Photography, exposure value (EV denotes all combinations of Camera Shutter speed and relative Aperture that give the same exposure For any given total exposure, or exposure value, a fast shutter speed requires a larger aperture (smaller f-number). Similarly, a slow shutter speed, a longer length of time, can be compensated by a smaller aperture (larger f-number).

Slow shutter speeds are often used in low light conditions, extending the time until the shutter closes, and increasing the amount of light gathered. This basic principle of photography, the exposure, is used in film and digital cameras, the image sensor effectively acting like film when exposed by the shutter. Many compact digital still cameras can record Sound and moving Video as well as still Photograph.

Shutter speed is measured in seconds. The second ( SI symbol s) sometimes abbreviated sec, is the name of a unit of Time, and is the International System of Units A typical shutter speed for photographs taken in sunlight is 1/125th of a second. In addition to its effect on exposure, shutter speed changes the way movement appears in the picture. Very short shutter speeds are used to freeze fast-moving subjects, for example at sporting events. Very long shutter speeds are used to intentionally blur a moving subject for artistic effect. ^[1]

Adjustment to the aperture controls the depth of field, the distance range over which objects are acceptably sharp; such adjustments generally need to be compensated by changes in the shutter speed. In Optics, particularly as it relates to Film and Photography, the depth of field (DOF is the portion of a scene that appears sharp in the image

In early days of photography, available shutter speeds were somewhat ad hoc. Ad hoc is a Latin phrase which means "for this [ Purpose ]" ^[2] Following the adoption of a standardized way of representing aperture so that each major step exactly doubled or halved the amount of light entering the camera (f/2. 8, f/4, f/5. 6, f/8, f/11, f/16, etc. ), a standardized 2:1 scale was adopted for shutter speed so that opening one aperture stop and reducing the shutter speed by one step resulted in the identical exposure. The agreed standards for shutter speeds are:^[3]

• 1/1000 s
• 1/500 s
• 1/250 s
• 1/125 s
• 1/60 s
• 1/30 s
• 1/15 s
• 1/8 s
• 1/4 s
• 1/2 s
• 1 s

Each standard increment either doubles the amount of light (longer time) or halves the amount of light (shorter time). For example, if you move from 1 sec to 1/2 second, you have effectively halved the amount of light entering the shutter. This scale can be extended at either end in specialist cameras. Some older cameras use the 2:1 ratio at slightly different values, such as 1/100 s and 1/50 s, although mechanical shutter mechanisms were rarely precise enough for the difference to have any significance.

The term "speed" is used in reference to short exposure times as fast, and long exposure times as slow. Shutter speeds are often designated by the reciprocal time, for example 60 for 1/60 s.

Camera shutters often include one or two other settings for making very long exposures:

• B (for bulb) — keep the shutter open as long as the shutter release is held
• T (for time) — keep the shutter open until the shutter release is pressed again

An Avro Lancaster over Hamburg — the curved streaking is caused by a combination of the movement of the photographing aircraft and the long exposure time required for taking photographs at night. Bulb is a shutter-speed setting on an adjustable camera that allows for long exposures under user control "Lanc" redirects here Distinguish from Lank (adjective and from Amon Lanc (a place in Tolkien's fiction Hamburg (English, German: ˈhambʊɐk local pronunciation Low German / Low Saxon: Hamborg) is the second-largest city in Germany

The ability of the photographer to take images without noticeable blurring by camera movement is an important parameter in the choice of slowest possible shutter speed for a handheld camera. The rough guide used by most 35 mm photographers is that the slowest shutter speed that can be used easily without much blur due to camera shake is the shutter speed numerically closest to the lens focal length. For example, for handheld use of a 35 mm camera with a 50 mm normal lens, the closest shutter speed is 1/60 s. In Photography and Cinematography a normal lens is a lens that generates images that generally look "natural" to a human observer under normal This rule can be augmented with knowledge of the intended application for the photograph, an image intended for significant enlargement and closeup viewing would require faster shutter speeds to avoid obvious blur. Through practice and special techniques such as bracing the camera, arms, or body to minimize camera movement longer shutter speeds can be used without blur. If a shutter speed is too slow for hand holding, a camera support — usually a tripod — must be used. In Photography, a tripod is a three-legged stand for a Camera, used to stabilize and elevate the camera Image stabilization can often permit the use of shutter speeds 3-4 stops slower (exposures 8-16 times longer). Image stabilization ( IS) is a family of techniques to increase the stability of an image

Shutter priority refers to a shooting mode used in semi-automatic cameras. It allows the photographer to choose a shutter speed setting and allow the camera to decide the correct aperture. This is sometimes referred to as Shutter Speed Priority Auto Exposure, or Tv (time value) mode. Shutter priority refers to a setting on some cameras that allows the user to choose a specific Shutter speed while the camera adjusts the Aperture to ensure correct

Creative utility in photography

Main article: Motion blur

Shutter speed is one of several methods used to control the amount of light recorded by the camera's digital sensor or film. Motion blur is the apparent streaking of rapidly moving objects in a still image or a sequence of images such as a movie or Animation. An image sensor is a device that converts an optical image to an electric signal It is also used to manipulate the visual effects of the final image beyond its luminosity.

Slower shutter speeds are often selected to suggest movement in a still photograph of a moving subject.

Excessively fast shutter speeds can cause a moving subject to appear unnaturally frozen. For instance, a running person may be caught with both feet in the air with all indication of movement lost in the frozen moment.

When a slower shutter speed is selected, a longer time passes from the moment the shutter opens till the moment it closes. More time is available for movement in the subject to be recorded by the camera.

A slightly slower shutter speed will allow the photographer to introduce an element of blur, either in the subject, where, in our example, the feet, which are the fastest moving element in the frame, might be blurred while the rest remains sharp; or if the camera is panned to follow a moving subject, the background is blurred while the subject remains sharp. Panning refers to the horizontal movement or rotation of a film or video camera or the scanning of a subject horizontally on video or a display device

The exact point at which the background or subject will start to blur depends on the rate at which the object is moving, the distance it is from the camera and the focal length of the lens in relation to the size of the digital sensor or film.

When slower shutter speeds, in excess of about half a second, are used on running water, the photo will have a ghostly white appearance reminiscent of fog. Fog is a cloud that is in contact with the ground Stratus clouds are usually the only clouds that touch the ground This effect can be used in landscape photography. Nature photography refers to a wide range of Photography taken outdoors and devoted to displaying natural elements such as Landscapes Wildlife,

Zoom burst is a technique which entails the variation of the focal length of a zoom lens during a longer exposure. In the moment that the shutter is opened, the lens is zoomed in, changing the focal length during the exposure. The center of the image remains sharp, while the details away from the center form a radial blur, which causes a strong visual effect, forcing the eye into the center of the image. ^[4]

Cinematographic shutter formula

In cinematography, shutter speed is a function of the frame rate and shutter angle. See also Filmmaking Cinematography (from Greek: kinesis κινησις (movement and grapho γραφω (to record is the discipline Frame rate, or frame frequency, is the measurement of the Frequency (rate at which an imaging device produces unique consecutive images called frames The Motion picture cameras film is exposed as a pie-shaped mirror called a rotary disc shutter, rotates in front of the Film gate. Most motion picture film cameras use a rotating shutter with a shutter angle of 165° or 180°, which leaves the film exposed for about 1/48 or 1/50 second at a standard 24 frame/s. Motion picture cameras film is exposed as a pie-shaped mirror called a rotary disc shutter, rotates in front of the Film gate. ^[5]

Where E = Exposure, F = Frames per second, and S = Shutter angle:^[5]

References

See also

• exposure
• shutter
• f-number
• exposure value