In photography, shutter speed or exposure time is the length of time when the film or digital sensor inside the camera is exposed to light, also when a camera's shutter is open when taking a photograph.
The amount of light that reaches the film or image sensor is proportional to the exposure time. 1⁄500 of a second will let half as much light in as 1⁄250.
In photography, exposure is the amount of light per unit area reaching a photographic film or electronic image sensor, as determined by shutter speed, lens aperture and scene luminance. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance in a specified region.
High-dynamic-range imaging (HDRI) is a high dynamic range (HDR) technique used in imaging and photography to reproduce a greater dynamic range of luminosity than is possible with standard digital imaging or photographic techniques. The aim is to present a similar range of luminance to that experienced through the human visual system. The human eye, through adaptation of the iris and other methods, adjusts constantly to adapt to a broad range of luminance present in the environment. The brain continuously interprets this information so that a viewer can see in a wide range of light conditions.
Heat capacity or thermal capacity is a measurable physical quantity equal to the ratio of the heat added to an object to the resulting temperature change. The unit of heat capacity is joule per kelvin
, or kilogram metre squared per kelvin second squared
in the International System of Units (SI). The dimensional form is L2MT−2Θ−1. Specific heat is the amount of heat needed to raise the temperature of one kilogram of mass by 1 kelvin.
In photography, exposure value (EV) is a number that represents a combination of a camera's shutter speed and f-number, such that all combinations that yield the same exposure have the same EV. Exposure value is also used to indicate an interval on the photographic exposure scale, with a difference of 1 EV corresponding to a standard power-of-2 exposure step, commonly referred to as a stop.
A normal mode of an oscillating system is a pattern of motion in which all parts of the system move sinusoidally with the same frequency and with a fixed phase relation. The free motion described by the normal modes takes place at the fixed frequencies. These fixed frequencies of the normal modes of a system are known as its natural frequencies or resonant frequencies. A physical object, such as a building, bridge, or molecule, has a set of normal modes and their natural frequencies that depend on its structure, materials and boundary conditions. When relating to music, normal modes of vibrating instruments are called "harmonics" or "overtones".
Power over Ethernet or PoE describes any of several standard or ad-hoc systems which pass electric power along with data on twisted pair Ethernet cabling. This allows a single cable to provide both data connection and electric power to devices such as wireless access points, IP cameras, and VoIP phones.
An autofocus optical system uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system has to be done manually until indication. Autofocus methods are distinguished by their type as being either active, passive or hybrid variants.
Shutter priority, also called time value, 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 exposure. This is different from manual mode, where the user must decide both values, aperture priority where the user picks an aperture with the camera selecting the shutter speed to match, or program mode where the camera selects both.
Time-lapse photography is a technique whereby the frequency at which film frames are captured is much more spread out than the frequency used to view the sequence. When played at normal speed, time appears to be moving faster and thus lapsing. For example, an image of a scene may be captured at 1 frame per second, but then played back at 30 frames per second; the result is an apparent 30 times speed increase. In a similar manner, film can also be played at a much lower rate than it was captured at, slowing down an otherwise fast action, as in slow motion or high-speed photography.
In photography, through-the-lens (TTL) 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. It was first used in Zeiss' Contax S of 1949; this East German branch of Zeiss also sold cameras under the Pentacon name; after merger with other East German photographic manufacturers, the name Praktica was used. M42 thread mount cameras first became well known under the Praktica brand, and thus the M42 mount is known as the Praktica thread mount. Since there were no proprietary elements to the M42 mount, many other manufacturers used it; this has led to it being called the Universal thread mount or Universal screw mount by many. The M42 mount was popularized in the United States by Pentax; thus, it is also known as the Pentax thread mount, despite the fact that Pentax did not originate it.
The EOS-1N is a 35mm single lens reflex (SLR) camera body produced by Canon. It was announced by Canon in 1994, and was the professional model in the range, superseding the original EOS-1. The camera was itself superseded by the EOS-1v in 2000.
Exposure compensation is a technique for adjusting the exposure indicated by a photographic exposure meter, in consideration of factors that may cause the indicated exposure to result in a less-than-optimal image. Factors considered may include unusual lighting distribution, variations within a camera system, filters, non-standard processing, or intended underexposure or overexposure. Cinematographers may also apply exposure compensation for changes in shutter angle or film speed, among other factors.
Note: If you came here to get a quick understanding of numbers like 1/2.3, skip ahead to table of sensor formats and sizes. For a simplified discussion of image sensors see image sensor.
Most digital cameras support the ability to choose among a number of configurations, or modes, for use in various situations. Professional DSLR cameras provide several manual modes; consumer point-and-shoot cameras emphasize automatic modes; and amateur prosumer cameras often have a wide variety of both manual and automatic modes.
The Samsung SGH-E250i mobile was introduced in 2009 as a dual band variant version of the tri band Samsung SGH-E250.
The Canon EOS 600D is an 18.0 megapixel digital single-lens reflex camera, released by Canon on 7 February 2011. It is known as the EOS Kiss X5 in Japan and the EOS Rebel T3i in America. The 600D is the second Canon EOS camera with an articulating LCD screen and supersedes the 550D, although the earlier model was not discontinued until June 2012, when the successor of the 600D, the 650D, was announced.
Aperture value may refer to:
