A reflex finder is a viewfinder system with a mirror placed behind a lens. The light passing through the lens is reflected by the mirror to a focusing screen, usually ground glass. The image formed on this ground glass can be observed directly, giving a waist-level reflex finder, or through a redressing optical device (set of mirrors or prism) for eye-level viewing, giving an eye-level reflex finder.
With a reflex finder, a photographer may focus the image on the ground glass and frame the picture at the same time. It is common to find a device on the center of the ground glass to help precise focusing, for example a split-image or a microprism device. Today's reflex cameras usually incorporate autofocusing.
Reflex finders are found in:
Single-lens reflex (SLR) cameras, with one lens for both viewing and taking the picture
Twin-lens reflex (TLR) cameras, with one lens for viewing and one lens for taking the picture
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 camera is an instrument used to capture and store images and videos, either digitally via an electronic image sensor, or chemically via a light-sensitive material such as photographic film. As a pivotal technology in the fields of photography and videography, cameras have played a significant role in the progression of visual arts, media, entertainment, surveillance, and scientific research. The invention of the camera dates back to the 19th century and has since evolved with advancements in technology, leading to a vast array of types and models in the 21st century.
A rangefinder camera is a camera fitted with a rangefinder, typically a split-image rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus.
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.
In photography and cinematography, a wide-angle lens is a lens covering a large angle of view. Conversely, its focal length is substantially smaller than that of a normal lens for a given film plane. This type of lens allows more of the scene to be included in the photograph, which is useful in architectural, interior, and landscape photography where the photographer may not be able to move farther from the scene to photograph it.
A pentaprism is a five-sided reflecting prism used to deviate a beam of light by a constant 90°, even if the entry beam is not at 90° to the prism. The beam reflects inside the prism twice, allowing the transmission of an image through a right angle without inverting it as an ordinary right-angle prism or mirror would.
In photography, a viewfinder is a small window the photographer looks through to see what a photo will look like before they capture it.
A digital single-lens reflex camera is a digital camera that combines the optics and mechanisms of a single-lens reflex camera with a solid-state image sensor and digitally records the images from the sensor.
Ground glass is glass whose surface has been ground to produce a flat but rough (matte) finish, in which the glass is in small sharp fragments.
The Canon EOS RT is a 35mm single-lens reflex camera produced by Canon and sold from 1989 to 1992. The camera is essentially an EOS 630/EOS 600 with a pellicle mirror. Only 25,000 were manufactured at the end of the EOS 630 production run, so the EOS RT was technically "out of production" before it ever went on sale.
A focusing screen is a flat translucent material, either a ground glass or Fresnel lens, found in a system camera that allows the user of the camera to preview the framed image in a viewfinder. Often, focusing screens are available in variants with different etched markings for various purposes. For instance, when photographing landscapes, a focusing screen with a grid allows the photographer to keep the horizon straight. Modern mirrorless cameras do not need a focusing screen since they display what the image sensor sees on a flat-panel display or electronic viewfinder.
The Canon Pellix is a manual-focus single-lens reflex (SLR) camera released in 1965 that uses a stationary half-silvered mirror behind which a metering cell is raised during light level metering.
In the field of photography, a manual focus camera is one in which the user has to adjust the focus of the lens by hand. Before the advent of autofocus, all cameras had manually adjusted focusing; thus, the term is a retronym.
A pellicle mirror is an ultra-thin, ultra-lightweight semi-transparent mirror employed in the light path of an optical instrument, splitting the light beam into two separate beams, both of reduced light intensity. Splitting the beam allows its use for multiple purposes simultaneously. The thinness of the mirror practically eliminates beam or image doubling due to a non-coincident weak second reflection from the nominally non-reflecting surface, a problem with mirror-type beam splitters. The name pellicle is a diminutive of pellis, a skin or film.
A director's viewfinder or director's finder is a viewfinder used by film directors and cinematographers to set the framing of a motion picture or movie camera. There are three types of director's viewfinders.
The Kodak Stereo Camera was a 35mm film stereo camera produced between 1954 and 1959. Similar to the Stereo Realist, the camera employed two lenses to take twin shots of scenes, which could then be viewed in dedicated image viewers. The lenses supported adjustable apertures and variable shutter speeds. The camera had a reputation for being easy to use, and sold approximately 100,000 units during the time it was produced.
A reflector sight or reflex sight is an optical sight that allows the user to look through a partially reflecting glass element and see an illuminated projection of an aiming point or some other image superimposed on the field of view. These sights work on the simple optical principle that anything at the focus of a lens or curved mirror will appear to be sitting in front of the viewer at infinity. Reflector sights employ some form of "reflector" to allow the viewer to see the infinity image and the field of view at the same time, either by bouncing the image created by lens off a slanted glass plate, or by using a mostly clear curved glass reflector that images the reticle while the viewer looks through the reflector. Since the reticle is at infinity it stays in alignment with the device to which the sight is attached regardless of the viewer's eye position, removing most of the parallax and other sighting errors found in simple sighting devices.
Afocal photography, also called afocal imaging or afocal projection is a method of photography where the camera with its lens attached is mounted over the eyepiece of another image forming system such as an optical telescope or optical microscope, with the camera lens taking the place of the human eye.
Through the Viewfinder (TtV) photography is a photographic or videographic technique in which a photograph or video or motion picture film is shot with one camera through the viewfinder of a second camera. The viewfinder thus acts as a kind of lens filter. The most popular method involves using a digital camera as the image taking camera and an intact twin-lens reflex camera (TLR) or pseudo-TLR as the "viewfinder" camera. TLRs typically have square waist-level viewfinders, with the viewfinder plane at 90 degrees to the image plane. The image in a TLR viewfinder is laterally reversed, i.e. it is a mirror image. Most photographers use a cardboard tube or other apparatus connecting the two cameras in order to eliminate stray light and prevent reflections from appearing on the viewfinder glass or on the lens of the imaging camera.
The Kine Exakta was the first 35mm single-lens reflex (SLR) still camera in regular production. It was presented by Ihagee Kamerawerk Steenbergen GmbH, Dresden at the Leipziger Frühjahrsmesse in March 1936. The Exakta name had already been used by Ihagee on a roll film rangefinder RF camera line since 1933, among these the Vest Pocket Exakta Model B from which the Kine Exakta inherited its general layout and appearance. The word Kine never appeared on the camera itself, only in the instruction manuals and advertising to distinguish it from the roll film variants. Several of its features constituted the foundation for the majority of 35mm SLR cameras produced ever since, although at this stage in a relatively primitive state.
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