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.
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane.
A camera is an optical instrument that captures images. Most cameras can capture 2D images, while some more advanced models can capture 3D images. At a basic level, most cameras consist of a sealed box with a small hole that allows light to pass through and capture an image on a light-sensitive surface. Cameras have various mechanisms to control how light falls onto the light-sensitive surface, including lenses that focus the light and a shutter that determines the amount of time the photosensitive surface is exposed to the light.
A pinhole camera is a simple camera without a lens but with a tiny aperture —effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the camera obscura effect. The size of the images depends on the distance between the object and the pinhole.
A view camera is a large-format camera in which the lens forms an inverted image on a ground-glass screen directly at the film plane. The image is viewed and then the glass screen is replaced with the film, and thus the film is exposed to exactly the same image as was seen on the screen.
A twin-lens reflex camera (TLR) is a type of camera with two objective lenses of the same focal length. One of the lenses is the photographic objective or "taking lens", while the other is used for the viewfinder system, which is usually viewed from above at waist level.
An f-number is a measure of the light-gathering ability of an optical system such as a camera lens. It is calculated by dividing the system's focal length by the diameter of the entrance pupil. The f-number is also known as the focal ratio, f-ratio, or f-stop, and it is a key factor in determining the depth of field, diffraction, and exposure of a photograph. The f-number is a dimensionless number that is usually expressed using a lower-case hooked f with the format f/‘‘N’’, where ‘‘N’’ is the f-number.
A camera lens is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.
In photography, flash synchronization or flash sync is the synchronizing the firing of a photographic flash with the opening of the shutter admitting light to photographic film or electronic image sensor.
Macro photography is extreme close-up photography, usually of very small subjects and living organisms like insects, in which the size of the subject in the photograph is greater than life size . By the original definition, a macro photograph is one in which the size of the subject on the negative or image sensor is life size or greater. In some senses, however, it refers to a finished photograph of a subject that is greater than life size.
A lens mount is an interface – mechanical and often also electrical – between a photographic camera body and a lens. It is a feature of camera systems where the body allows interchangeable lenses, most usually the rangefinder camera, single lens reflex type, single lens mirrorless type or any movie camera of 16 mm or higher gauge. Lens mounts are also used to connect optical components in instrumentation that may not involve a camera, such as the modular components used in optical laboratory prototyping which join via C-mount or T-mount elements.
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.
Large format lenses are photographic optics that provide an image circle large enough to cover the large format film or plates used in large format cameras.
The following are common definitions related to the machine vision field.
A C mount is a type of lens mount commonly found on 16 mm movie cameras, closed-circuit television cameras, machine vision cameras and microscope phototubes.
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 Kodak Retina Reflex is a discontinued series of four single-lens reflex cameras made by Kodak in Germany between 1957 and 1974, as part of the Kodak Retina line of 35mm film cameras.
The design of photographic lenses for use in still or cine cameras is intended to produce a lens that yields the most acceptable rendition of the subject being photographed within a range of constraints that include cost, weight and materials. For many other optical devices such as telescopes, microscopes and theodolites where the visual image is observed but often not recorded the design can often be significantly simpler than is the case in a camera where every image is captured on film or image sensor and can be subject to detailed scrutiny at a later stage. Photographic lenses also include those used in enlargers and projectors.
Plaubel is a German camera maker, founded in November, 1902, by Hugo Schrader, who learned the technology of cameras and lenses as an apprentice at Voigtländer in Braunschweig in the late 1800s before being employed by a Frankfurt camera and lens manufacturer and distributor, Dr. R. Krügener, whose daughter he married. Hugo Schrader and his wife elected to open their own business, Plaubel & Co., as distributors and makers of cameras and lenses, naming it after his brother-in-law because he thought Plaubel was easier to remember than Schrader.
Friedrich Deckel GmbH, also known as F.Deckel, was a German company founded by Friedrich Deckel and Christian Bruns in Munich as Bruns & Deckel in 1903. Its most famous product is the Compur line of leaf shutters used on many photographic lenses starting from 1911. Bruns and Deckel previously had worked together at C. A. Steinheil & Söhne; Bruns was an inventor responsible for developing leaf shutters while Deckel was a laboratory mechanic.
