Mirror lock-up

Last updated
With mirror lock-up the mirror (2) flips up towards (5) well before the shutter (3) opens. As a result, light no longer reaches the eyepiece (8). SLR cross section.svg
With mirror lock-up the mirror (2) flips up towards (5) well before the shutter (3) opens. As a result, light no longer reaches the eyepiece (8).

Mirror lock-up (often abbreviated to MLU) is a feature employed in many Single Lens Reflex (SLR) cameras. It allows the operator to reduce vibration-induced motion blur during exposure. It also allows the mounting of lenses which extend into the SLR's mirror box when mounted.

Contents

Reducing vibration

Normal operation in an SLR camera involves flipping the mirror up out of the light-path just before the shutter opens, and then returning it when the shutter closes (although very early SLR's required the shutter to be cocked for the mirror to return). This causes vibration of the camera, particularly when the mirror slaps into the top of the mirror box. This vibration quickly dies away so the most motion blur is actually seen with short shutter times that capture multiple 'swings' of the vibration (shutter speeds of 1/2 to 1/60 second are often affected by this). While longer exposures will capture all of the vibrations, the exposure will be dominated by light captured when the camera is vibration-free (assuming a steady mount).

Mirror lock-up involves flipping the mirror up well before the shutter opens, allowing the vibrations to die down before exposing the film. On some cameras MLU may be operated by an extra push of the shutter button, the second push resulting in the actual opening of the shutter. Other arrangements may involve an extra lever or button that flips the mirror up before using the shutter release button normally. On some cameras MLU is not a separate feature, but operated as part of the self timer (notably the Nikon FE line of cameras).

Note that when the mirror is in the up and locked position, the subject is no longer visible through the viewfinder. Therefore, the photographer must compose the photograph prior to activating mirror lock-up and keep the camera from moving. Use of a tripod helps prevent movement of the camera during this operation.

Combined with a remote or cable release, this greatly reduces the potential for vibration of the camera.

Lenses requiring mirror lock-up

Some lenses are designed such that they extend into the mirror box when properly mounted on an SLR. These may include early wide-angle lenses for SLR's, certain lenses designed for rangefinder cameras, and certain other non-SLR lenses adapted for SLR use. Mirror lock-up must be activated prior to mounting such lenses, and kept in place in order to prevent damage to the lens or camera. This method of operation prevents any use of the SLR viewfinder with the lens. Prior to the development of lenses utilizing the Angénieux retrofocus concept, mirror lock-up was essential to wide-angle SLR photography.

Related Research Articles

Single-lens reflex camera Camera that typically uses a mirror and prism system

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.

Camera Optical device for recording images

A camera is an optical instrument that captures a visual image. At a basic level, cameras are sealed boxes with a small hole that allows light through to capture an image on a light-sensitive surface. Cameras have various mechanisms to control how the light falls onto the light-sensitive surface. Lenses focus the light entering the camera, and the size of the aperture can be widened or narrowed. A shutter mechanism determines the amount of time the photosensitive surface is exposed to light.

Nikon FM

The Nikon FM is a mechanically operated, interchangeable lens, 35 mm film, single-lens reflex (SLR) camera. It was manufactured in Japan between 1977 and 1982 by Nippon Kogaku K. K..

Nikon F6

The Nikon F6 is a 35 mm film single-lens reflex camera body that became commercially available during 2004, and is the sixth top-of-the-line professional film camera in Nikon's line since the introduction of the Nikon F in 1959. The Nikon F6 is designed by Nikon and was manufactured at their Sendai Plant.

Viewfinder

In photography, a viewfinder is what the photographer looks through to compose, and, in many cases, to focus the picture. Most viewfinders are separate, and suffer parallax, while the single-lens reflex camera lets the viewfinder use the main optical system. Viewfinders are used in many cameras of different types: still and movie, film, analog and digital. A zoom camera usually zooms its finder in sync with its lens, one exception being rangefinder cameras.

Pentax Auto 110

The Pentax Auto 110 and Pentax Auto 110 Super are single-lens reflex cameras made by Asahi Pentax that use Kodak's 110 film cartridge. The Auto 110 was introduced with three interchangeable lenses in 1978. Three more lenses were introduced in 1981, and then the Super model was released in 1982. 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.

Digital single-lens reflex camera Digital cameras combining the parts of a single-lens reflex camera and a digital camera back

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 digital imaging sensor.

Kiev is a Soviet and Ukrainian brand of photographic equipment including cameras manufactured by the Arsenal Factory in Kiev, Ukraine. The camera nameplates show the name "KIEV", with older cameras using "КИЕВ" or "КИЇВ" in Cyrillic.

The science of photography is the use of chemistry and physics in all aspects of photography. This applies to the camera, its lenses, physical operation of the camera, electronic camera internals, and the process of developing film in order to take and develop pictures properly.

Nikon F3 Camera model

The Nikon F3 was Nikon's third professional single-lens reflex camera body, preceded by the F and F2. Introduced in 1980, it had manual and semi-automatic exposure control whereby the camera would select the correct shutter speed. The Nikon F3 series cameras had the most model variations of any Nikon F camera. It was also the first of numerous Nikon F-series cameras to be styled by Italian designer Giorgetto Giugiaro, and to include a red stripe on the handgrip – a feature that would later become a signature feature of many Nikon cameras.

Canon EF camera

The Canon EF is a manual focus 35mm single-lens reflex camera produced by Canon between 1973 and 1978. It was compatible with Canon's FD-mount lenses. The EF was built as an electro-mechanical version of Canon's top-of-the line wholly mechanical Canon F-1. The shutter is mechanical at all speeds starting at 1/2 second and faster, but from 1 second and beyond the shutter is all electric, allowing for AE shutter speeds as long as 30 seconds. The EF shares the F-1's rugged construction and tough metal body. Unlike the F-1, the EF does not support any motor drive for film transport. Neither does it provide any interchangeable viewfinder.

Canon T90

The Canon T90, introduced in 1986, was the top of the line in Canon's T series of 35 mm Single-lens reflex (SLR) cameras. It is the last professional-level manual-focus camera from Canon, and the last professional camera to use the Canon FD lens mount. Although it was overtaken by the autofocus revolution and Canon's new, incompatible EOS after only a year in production, the T90 pioneered many concepts seen in high-end Canon cameras up to the present day, particularly the user interface, industrial design, and the high level of automation.

The Olympus OM System was a line of 35mm single-lens reflex cameras, lenses and accessories sold by Olympus between 1972 and 2002. The system was introduced by Olympus in 1972. The range was designed by Yoshihisa Maitani, chief designer for Olympus, and his staff; OM stands for Olympus Maitani.

Canon EOS RT

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.

Image stabilization Techniques used to reduce blurring of images

Image stabilization (IS) is a family of techniques that reduce blurring associated with the motion of a camera or other imaging device during exposure.

Olympus E-330

The Olympus E-330 is a DSLR launched on 30 January 2006, using the Four Thirds System lens mount standard. Its main feature is its live image preview functionality, permitting an image to be previewed on the LCD screen. While live image preview is not new in compact digital cameras, the E-330 is significant because it was the first digital SLR to offer this feature. With the ability to digitally zoom in 10× before taking a picture, it is very well suited for exact manual focussing, for example in macro photography.

Konica Hexar RF

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.

Konica Autoreflex

The Auto-Reflex and Autoreflex is a series of 35mm SLR cameras made by Konica from 1965 to 1988. All these models have the Konica AR bayonet.

Pentax 6×7

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.

Fuji GX680

The Fuji GX680 is a series of single lens reflex system cameras for medium format film produced by Fujifilm with interchangeable camera lenses and interchangeable film holders for the unusual film format 6×8 cm on 120 and 220 roll film. The distinguishing feature of the Fuji GX680 is the articulating front standard, which runs on a rail connecting lens and camera body by a bellows; the interchangeable lens is permanently mounted to a lens board.

References