The Bulb setting (abbreviated B) on camera shutters is a momentary-action mode that holds shutters open for as long as a photographer depresses the shutter-release button. The Bulb setting is distinct from shutter's Time (T) setting, which is an alternate-action mode where the shutter opens when the shutter-release button is pressed and released once, and closes when the button is actuated again. [1] [2]
Decades before the first flashbulbs, some box cameras and many view cameras and folding cameras came with a detachable pneumatic shutter release with a rubber bulb on the end; "Bulb" refers to the rubber shutter release bulb. [3] Though mechanically timed exposures could also be triggered by squeezing the shutter release bulb, "Bulb" exposures then had the same momentary action as camera shutters have today, as per this description from Sears Roebuck's 1909 Cameras [&] Photographic Supplies:
With the indicator set to B, the shutter opens when the bulb is pressed and remains open as long as the pressure is maintained (“bulb” exposure), a very convenient means of making time exposures of only a few seconds’ duration.
Around 1894 in Germany, the momentary-action setting on camera shutters made by C. A. Steinheil & Söhne in Munich were denoted with "B" but the literature referred to it as Beliebig (meaning beliebige Zeit, English: "Any time").
The Eastman Kodak Company sold entry level consumer cameras that did not have the option of a pneumatic shutter release. Though Kodak retained the convention of using "B” on shutters to denote the setting that provides momentary actuation, they referred to it as "Brief Time" in brochures for cameras like their Folding Autographic Brownies, as well as in instruction manuals for products like their 1 & 1A Pocket "Kodaks" Juniors. "Brief time" was also used in reference works like Newnes Photographers' Pocket Reference Book (1955).
The bulb setting is used on some cameras, including some point-and-shoot cameras, to obtain shutter speeds slower than the minimum offered by the camera otherwise.
Because of the risk of camera movement, the camera is most often mounted on a tripod for the duration of the exposure. While it is generally possible to use the shutter release button on the camera itself, a cable release or electronic remote is often used to further eliminate the risk of shaking the camera during long exposures. The cable releases generally include a locking feature to eliminate the need to keep the button or plunger depressed during extremely long exposures.
The bulb setting is useful for the following types of photographic subjects:
On some modern cameras, bulb is a mode available as an option on the LCD menu only, if possible at all. On others, including many Digital SLR cameras, bulb is typically available from the manual exposure mode and—rarely—also from shutter priority mode. [4]
When set to bulb, generally on the "M" or manual setting of the camera, the shutter will stay open as long as the shutter release button (or shutter release cable or remote) remains depressed.
Some mid-level or bridge cameras such as the Olympus SP-560UZ have a 'limited' bulb setting, allowing time exposures up to 8 minutes and at an ISO setting of 200 ISO and lower. [5]
In 2012, Olympus introduced a new form of bulb mode with their "Live Bulb" (without toggle) and "Live Time" (with toggle) settings in their Olympus OM-D E-M5 digital camera, where the viewfinder and display gets updated during the exposure in order to allow the photographer to inspect the exposure while it "develops". The display refresh rate for this mode can be configured between 0.5 s and 60 s.
Some specialized cameras use other image triggers.
A single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final image. When the shutter button is pressed on most SLRs, the mirror flips out of the light path, allowing light to pass through to the light receptor and the image to be captured.
A flash is a device used in photography that produces a brief burst of light at a color temperature of about 5500 K to help illuminate a scene. A major purpose of a flash is to illuminate a dark scene. Other uses are capturing quickly moving objects or changing the quality of light. Flash refers either to the flash of light itself or to the electronic flash unit discharging the light. Most current flash units are electronic, having evolved from single-use flashbulbs and flammable powders. Modern cameras often activate flash units automatically.
In camera design, a focal-plane shutter (FPS) is a type of photographic shutter that is positioned immediately in front of the focal plane of the camera, that is, right in front of the photographic film or image sensor.
The Pentax Auto 110 and Pentax Auto 110 Super were fully automatic single-lens reflex cameras manufactured by Asahi Pentax for use with Kodak 110 film cartridges. The Auto 110 was introduced with three interchangeable, fixed focal length lenses in 1978. A further three lenses were added in 1981 to coincide with the release of the Auto 110 Super the following year. The camera system was sold until 1985. The complete system is sometimes known as the Pentax System 10, apparently for its official Pentax name, although most Pentax advertising only uses the camera name or Pentax-110. This model represented the only complete ultraminiature SLR system manufactured for the 110 film format, although several fixed-lens 110 SLRs were sold. The camera system also claims to be the smallest interchangeable-lens SLR system ever created.
A digital single-lens reflex camera is a digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a solid-state image sensor and digitally records the images from the sensor.
When setting photoflash exposures, the guide number (GN) of photoflash devices is a measure photographers can use to calculate either the required f‑stop for any given flash-to-subject distance, or the required distance for any given f‑stop. To solve for either of these two variables, one merely divides a device's guide number by the other.
The Canon A-1 is an advanced-level single-lens reflex (SLR) 35 mm film camera for use with interchangeable lenses. It was manufactured by Canon Camera K. K. in Japan from April 1978 to 1985. It employs a horizontal cloth-curtain focal-plane shutter with a speed range of 30 to 1/1000 second plus bulb and flash synchronization speed of 1/60 second. It has dimensions of 92 millimetres (3.6 in) height, 141 millimetres (5.6 in) width, 48 millimetres (1.9 in) depth and 620 grams (22 oz) weight. Unlike most SLRs of the time, it was available in only one color; all black. The introductory US list price for the body plus Canon FD 50 mm f/1.4 SSC lens was $625; the camera body was generally sold with a 30–40% discount.
In photography, a shutter is a device that allows light to pass for a determined period, exposing photographic film or a photosensitive digital sensor to light in order to capture a permanent image of a scene. A shutter can also be used to allow pulses of light to pass outwards, as seen in a movie projector or a signal lamp. A shutter of variable speed is used to control exposure time of the film. The shutter is constructed so that it automatically closes after a certain required time interval. The speed of the shutter is controlled either automatically by the camera based on the overall settings of the camera, manually through digital settings, or manually by a ring outside the camera on which various timings are marked.
In photography, through-the-lens metering refers to a feature of cameras whereby the intensity of light reflected from the scene is measured through the lens; as opposed to using a separate metering window or external hand-held light meter. In some cameras various TTL metering modes can be selected. This information can then be used to set the optimal film or image sensor exposure, it can also be used to control the amount of light emitted by a flash unit connected to the camera.
The M42 lens mount is a screw thread mounting standard for attaching lenses to 35 mm cameras, primarily single-lens reflex models. It is more accurately known as the M42 × 1 mm standard, which means that it is a metric screw thread of 42 mm diameter and 1 mm thread pitch.
The history of the single-lens reflex camera (SLR) begins with the use of a reflex mirror in a camera obscura described in 1676, but it took a long time for the design to succeed for photographic cameras. The first patent was granted in 1861, and the first cameras were produced in 1884, but while elegantly simple in concept, they were very complex in practice. One by one these complexities were overcome as optical and mechanical technology advanced, and in the 1960s the SLR camera became the preferred design for many high-end camera formats.
The Minolta XG-M was a 35mm single-lens reflex camera introduced in 1981 by Minolta of Japan. It was also known as the X-70 on the Japanese market, in which it was not available until 1982. When released, it was the top model in Minolta's XG series of consumer-grade manual focus SLRs, replacing the XG-9. Changes from that model included a metered manual mode, and a revised body style with rearranged controls. This was also the first camera to use Minolta's new logo, which was used until the 2003 merger into Konica Minolta.
The Olympus OM-4 is an interchangeable-lens, 35 mm film, single lens reflex (SLR) camera; manufactured by Olympus Optical Co., Ltd. in Japan, and sold as OM-4 from 1983 to 1987 and as OM-4Ti from 1986 to 2002.
Image stabilization (IS) is a family of techniques that reduce blurring associated with the motion of a camera or other imaging device during exposure.
APEX stands for Additive System of Photographic Exposure, which was proposed in the 1960 ASA standard for monochrome film speed, ASA PH2.5-1960, as a means of simplifying exposure computation.
The Pentax ME F was an amateur level, interchangeable lens, 35 mm film, single-lens reflex (SLR) camera. It was manufactured by Asahi Optical Co., Ltd. of Japan from November 1981 to 1984. The ME F was a heavily modified version of the Pentax ME-Super, and a member of the Pentax M-series family of SLRs. It was the first mass-produced SLR camera to come with an autofocus system.
The Konica Hexar RF is a 35 mm rangefinder camera which was sold by Konica. It was introduced to the market on 13 October 1999. and subsequently discontinued some time before the end of 2003. The camera used the "Bayonet Konica KM-mount", a copy of the Leica M-mount, thus sharing interchangeable lenses with those designed for Leica cameras and others compatible with them. The Hexar RF has a combined rangefinder/viewfinder modeled on that of Leica cameras, a similar body shape and size - and so is similar to Leica M-mount cameras in many aspects of operation.
The Konica Hexar is a 35 mm fixed-lens, fixed focal length autofocus camera which was produced through the 1990s. It was introduced to the market in 1993. While styled like a rangefinder camera, and intended for a similar style of photography, in specification it is more like a larger "point and shoot" camera.
The Pentax 6×7 is a SLR medium format system film camera for 120 and 220 film, which produces images on the film that are nominally 6 cm by 7 cm in size, made by Pentax. It originally debuted in 1965 as a prototype dubbed the Pentax 220. Since then, with improvements, it was released in 1969 as the Asahi Pentax 6×7, as well as the Honeywell Pentax 6×7 for the North American import market. In 1990, it received a number of minor engineering updates and cosmetic changes and was renamed as the Pentax 67.
The Olympus OM-D E-M5, announced in February 2012, is a Micro Four Thirds compact mirrorless interchangeable lens camera. In style and name it references the Olympus OM series of film SLR cameras, but it is not an SLR camera. The successor is the Olympus OM-D E-M5 Mark II.
BULB EXPOSURE (B). Another term for a brief exposure—in which the shutter remains open only so long as the shutter release is held down. The word originated with the early pneumatic shutter release.