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53-598: The M2 was considered to be a more affordable, simplified version of the 1954 Leica M3 . Notably, the frame counter of the M2 was composed of a disk plate beneath the film advance lever that had to be manually reset to zero after reloading. This system was close to that of the Leica III series, and unlike that of the M3, which is an independent frame counter, visible through a window in the top plate, that automatically resets to zero when

106-440: A graticule , not in actual contact with the display on an oscilloscope , etc. When viewed through a stereo viewer, aerial picture pair offers a pronounced stereo effect of landscape and buildings. High buildings appear to "keel over" in the direction away from the center of the photograph. Measurements of this parallax are used to deduce the height of the buildings, provided that flying height and baseline distances are known. This

159-466: A 50mm lens who sometimes find it difficult to see the framelines on the M3. The ground glass frameline illumination window of the M3 was replaced with a fresnel-type plastic lens. Finally, the ornate beveling around the various windows on the front of the M3 were flattened on the body of the M2. Unlike the M3, the widest framelines were not always visible so only one set of framelines were ever displayed at one time. All M2s are single stroke advance. The M2

212-442: A boy". In a philosophic/geometric sense: an apparent change in the direction of an object, caused by a change in observational position that provides a new line of sight. The apparent displacement, or difference of position, of an object, as seen from two different stations, or points of view. In contemporary writing, parallax can also be the same story, or a similar story from approximately the same timeline, from one book, told from

265-429: A change in viewpoint occurring due to the motion of the observer, of the observed, or both. What is essential is relative motion. By observing parallax, measuring angles , and using geometry , one can determine distance . Distance measurement by parallax is a special case of the principle of triangulation , which states that one can solve for all the sides and angles in a network of triangles if, in addition to all

318-691: A different perspective in another book. The word and concept feature prominently in James Joyce 's 1922 novel, Ulysses . Orson Scott Card also used the term when referring to Ender's Shadow as compared to Ender's Game . The metaphor is invoked by Slovenian philosopher Slavoj Žižek in his 2006 book The Parallax View , borrowing the concept of "parallax view" from the Japanese philosopher and literary critic Kojin Karatani . Žižek notes The philosophical twist to be added (to parallax), of course,

371-404: A higher level of uncertainty because the relative velocity of observed stars is an additional unknown. When applied to samples of multiple stars, the uncertainty can be reduced; the uncertainty is inversely proportional to the square root of the sample size. Moving cluster parallax is a technique where the motions of individual stars in a nearby star cluster can be used to find the distance to

424-460: A knob to advance the film. For fear of tearing the film, early M3s had a double stroke advance lever, like the Neoca 2s would. Later models (from model no 919 251) had single-stroke levers, which quickened up operation of the camera. Another type of variation is in the film pressure plate used. Early models used a glass plate to keep the film flat, whereas later models used a metal plate. Loading of

477-647: A miniature replica camera, the Digital Classic Camera Leica M3 , was made by Minox (by then bought by Leica). Mechanical |  Mechanical TTL   |   Electronic Controlled Shutter TTL   This article was originally based on " Leica M3 " in Camerapedia, retrieved on 7 May 2007 under the GNU Free Documentation License . Parallax Parallax is a displacement or difference in

530-737: A parallax larger than a few times the precision of the measurement. In the 1990s, for example, the Hipparcos mission obtained parallaxes for over a hundred thousand stars with a precision of about a milliarcsecond , providing useful distances for stars out to a few hundred parsecs. The Hubble Space Telescope 's Wide Field Camera 3 has the potential to provide a precision of 20 to 40 micro arcseconds, enabling reliable distance measurements up to 5,000 parsecs (16,000 ly) for small numbers of stars. The Gaia space mission provided similarly accurate distances to most stars brighter than 15th magnitude. Distances can be measured within 10% as far as

583-408: A ruler marked on its top surface, the thickness of the ruler will separate its markings from the ticks. If viewed from a position not exactly perpendicular to the ruler, the apparent position will shift and the reading will be less accurate than the ruler is capable of. A similar error occurs when reading the position of a pointer against a scale in an instrument such as an analog multimeter . To help

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636-399: Is a key component of the process of photogrammetry . Parallax error can be seen when taking photos with many types of cameras, such as twin-lens reflex cameras and those including viewfinders (such as rangefinder cameras ). In such cameras, the eye sees the subject through different optics (the viewfinder, or a second lens) than the one through which the photo is taken. As the viewfinder

689-465: Is also an issue in image stitching , such as for panoramas. Parallax affects sighting devices of ranged weapons in many ways. On sights fitted on small arms and bows , etc., the perpendicular distance between the sight and the weapon's launch axis (e.g. the bore axis of a gun)—generally referred to as " sight height "—can induce significant aiming errors when shooting at close range, particularly when shooting at small targets. This parallax error

742-615: Is compensated for (when needed) via calculations that also take in other variables such as bullet drop , windage , and the distance at which the target is expected to be. Sight height can be used to advantage when "sighting in" rifles for field use. A typical hunting rifle (.222 with telescopic sights) sighted in at 75m will still be useful from 50 to 200 m (55 to 219 yd) without needing further adjustment. In some reticled optical instruments such as telescopes , microscopes or in telescopic sights ("scopes") used on small arms and theodolites , parallax can create problems when

795-408: Is often found above the lens of the camera, photos with parallax error are often slightly lower than intended, the classic example being the image of a person with their head cropped off. This problem is addressed in single-lens reflex cameras , in which the viewfinder sees through the same lens through which the photo is taken (with the aid of a movable mirror), thus avoiding parallax error. Parallax

848-471: Is quite small, even for the nearest stars, measuring 1 arcsecond for an object at 1 parsec's distance (3.26 light-years ), and thereafter decreasing in angular amount as the distance increases. Astronomers usually express distances in units of parsecs (parallax arcseconds); light-years are used in popular media. Because parallax becomes smaller for a greater stellar distance, useful distances can be measured only for stars which are near enough to have

901-511: Is slightly larger. There are two ways to select the 90mm or 135mm framelines: Viewfinder cameras do not show exactly the same image in the viewfinder and on the film, due to the distance of the viewfinder to the view axis of the lens. This parallax problem is compensated in the M3 by moving the framelines when the lens is focused. This full parallax compensation is limited to one metre; closer distances require special "Leica glasses" as described above. The Leica IIIf and its predecessors had used

954-483: Is that the observed distance is not simply "subjective", since the same object that exists "out there" is seen from two different stances or points of view. It is rather that, as Hegel would have put it, subject and object are inherently "mediated" so that an " epistemological " shift in the subject's point of view always reflects an " ontological " shift in the object itself. Or—to put it in Lacanese —the subject's gaze

1007-399: Is used for computer stereo vision , and there is a device called a parallax rangefinder that uses it to find the range, and in some variations also altitude to a target. A simple everyday example of parallax can be seen in the dashboards of motor vehicles that use a needle-style mechanical speedometer . When viewed from directly in front, the speed may show exactly 60, but when viewed from

1060-567: The stellar parallax method . As the Earth orbits the Sun, the position of nearby stars will appear to shift slightly against the more distant background. These shifts are angles in an isosceles triangle , with 2 AU (the distance between the extreme positions of Earth's orbit around the Sun) making the base leg of the triangle and the distance to the star being the long equal-length legs. The amount of shift

1113-522: The Galactic Center , about 30,000 light years away. Stars have a velocity relative to the Sun that causes proper motion (transverse across the sky) and radial velocity (motion toward or away from the Sun). The former is determined by plotting the changing position of the stars over many years, while the latter comes from measuring the Doppler shift of the star's spectrum caused by motion along

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1166-403: The apparent position of an object viewed along two different lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to foreshortening , nearby objects show a larger parallax than farther objects, so parallax can be used to determine distances. To measure large distances, such as the distance of a planet or a star from Earth , astronomers use

1219-614: The Leica, among them the combination of viewfinder and rangefinder in one bright window, like on the Contax II , a bayonet lens mount, and rapid film advance lever. It was the most successful model of the M series, with over 220,000 units sold by the time production of the M3 model ended in 1966. It was succeeded by a number of later film M series cameras , including the Leica M-A film camera in 2014. The earliest Leica M3 pre-model that

1272-530: The M2's framelines have proved to be more versatile over time, with all subsequent Leica rangefinder models having 35mm framelines included. There are a number of variations of the Leica M2. Although most models have the self-timer lever, it is absent from some earlier models. Also, some early models have a film rewind push-button instead of the typical lever. About 2400 M2s were factory-painted black, but these are relatively rare and more valued by collectors. Near

1325-423: The M3 was sold), and a simple adapter also allows the use of screwmount lenses (whether from Leitz or other companies). The M3 has an exceptionally bright viewfinder when compared to any previous or subsequent model, including the modern M9. The M3 has a high magnification factor of 0.91×, which is useful in critical focusing, and especially with long lenses (subsequent Leicas would use 0.85×, 0.72× or 0.58×). It

1378-554: The Sun through space provides a longer baseline that will increase the accuracy of parallax measurements, known as secular parallax . For stars in the Milky Way disk, this corresponds to a mean baseline of 4 AU per year, while for halo stars the baseline is 40 AU per year. After several decades, the baseline can be orders of magnitude greater than the Earth–Sun baseline used for traditional parallax. However, secular parallax introduces

1431-429: The angles in the network, the length of at least one side has been measured. Thus, the careful measurement of the length of one baseline can fix the scale of an entire triangulation network. In parallax, the triangle is extremely long and narrow, and by measuring both its shortest side (the motion of the observer) and the small top angle (always less than 1  arcsecond , leaving the other two close to 90  degrees),

1484-438: The camera rotated during firing). The M3 combined slower and faster speeds and the dial does not rotate during firing. Supposedly, this reduces vibrations in the camera. Early models used a non-geometrical series of shutter speeds. On later models this became the international standard of 1s to 1/1000s. Variants of the M3 were made for specific purposes. The Leica 24x27 was a camera with neither rangefinder nor viewfinder, made for

1537-597: The cluster. Only open clusters are near enough for this technique to be useful. In particular the distance obtained for the Hyades has historically been an important step in the distance ladder. Other individual objects can have fundamental distance estimates made for them under special circumstances. If the expansion of a gas cloud, like a supernova remnant or planetary nebula , can be observed over time, then an expansion parallax distance to that cloud can be estimated. Those measurements however suffer from uncertainties in

1590-462: The deviation of the object from sphericity. Binary stars which are both visual and spectroscopic binaries also can have their distance estimated by similar means, and do not suffer from the above geometric uncertainty. The common characteristic to these methods is that a measurement of angular motion is combined with a measurement of the absolute velocity (usually obtained via the Doppler effect ). The distance estimate comes from computing how far

1643-560: The different views from the eye to gain depth perception and estimate distances to objects. Animals also use motion parallax , in which the animals (or just the head) move to gain different viewpoints. For example, pigeons (whose eyes do not have overlapping fields of view and thus cannot use stereopsis) bob their heads up and down to see depth. The motion parallax is exploited also in wiggle stereoscopy , computer graphics that provide depth cues through viewpoint-shifting animation rather than through binocular vision. Parallax arises due to

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1696-460: The distance to Proxima Centauri is 1/0.7687 = 1.3009 parsecs (4.243 ly). On Earth, a coincidence rangefinder or parallax rangefinder can be used to find distance to a target. In surveying , the problem of resection explores angular measurements from a known baseline for determining an unknown point's coordinates. The most important fundamental distance measurements in astronomy come from trigonometric parallax, as applied in

1749-569: The end of production, Leica also produced a number of M2-R models, which had the faster loading system of the later Leica M4. Mechanical |  Mechanical TTL   |   Electronic Controlled Shutter TTL   Leica M3 The Leica M3 is a 35 mm rangefinder camera by Ernst Leitz GmbH (now Leica Camera AG ), introduced in 1954. It was a new starting point for Leitz, which until then had only produced screw-mount Leica cameras that were incremental improvements to its original Leica (Ur-Leica). The M3 introduced several features to

1802-602: The film is done by removing the bottom plate, like on the Leica II and III series. A door flap on the rear of the camera can be raised, allowing for easier access to the film, thereby overcoming a problem associated with these earlier screw-lens-type Leicas. The film is inserted from the bottom of the camera after the user has pre-attached the leading end to the take-up spool. Special cassettes were also available. Previous screw mount Leicas used two separate shutter speed dials for slow and fast speeds (the fast speed dial on top of

1855-436: The film take-up spool is removed. The rangefinder system was also simplified from that of the M3 and this made it potentially more prone to rangefinder flare. The M2 has a rangefinder with a 0.72 magnification and framelines for 35, 50 and 90mm lenses instead of the 0.91 magnification and 50, 90 and 135mm framelines of the M3. This made it better suited for photojournalists who favour shorter lenses or for spectacle-wearers using

1908-1116: The focus of the target image at varying distances into the same optical plane of the reticle (or vice versa). Many low-tier telescopic sights may have no parallax compensation because in practice they can still perform very acceptably without eliminating parallax shift. In this case, the scope is often set fixed at a designated parallax-free distance that best suits their intended usage. Typical standard factory parallax-free distances for hunting scopes are 100  yd (or 90 m) to make them suited for hunting shots that rarely exceed 300  yd/m. Some competition and military-style scopes without parallax compensation may be adjusted to be parallax free at ranges up to 300  yd/m to make them better suited for aiming at longer ranges. Scopes for guns with shorter practical ranges, such as airguns , rimfire rifles , shotguns , and muzzleloaders , will have parallax settings for shorter distances, commonly 50 m (55 yd) for rimfire scopes and 100 m (110 yd) for shotguns and muzzleloaders. Airgun scopes are very often found with adjustable parallax, usually in

1961-407: The form of an adjustable objective (or "AO" for short) design, and may adjust down to as near as 3 metres (3.3 yd). Non-magnifying reflector or "reflex" sights can be theoretically "parallax free". But since these sights use parallel collimated light this is only true when the target is at infinity. At finite distances, eye movement perpendicular to the device will cause parallax movement in

2014-406: The higher rungs of the ladder. Parallax also affects optical instruments such as rifle scopes, binoculars , microscopes , and twin-lens reflex cameras that view objects from slightly different angles. Many animals, along with humans, have two eyes with overlapping visual fields that use parallax to gain depth perception ; this process is known as stereopsis . In computer vision the effect

2067-435: The length of the long sides (in practice considered to be equal) can be determined. In astronomy, assuming the angle is small, the distance to a star (measured in parsecs ) is the reciprocal of the parallax (measured in arcseconds ): d ( p c ) = 1 / p ( a r c s e c ) . {\displaystyle d(\mathrm {pc} )=1/p(\mathrm {arcsec} ).} For example,

2120-480: The line of sight. For a group of stars with the same spectral class and a similar magnitude range, a mean parallax can be derived from statistical analysis of the proper motions relative to their radial velocities. This statistical parallax method is useful for measuring the distances of bright stars beyond 50 parsecs and giant variable stars , including Cepheids and the RR Lyrae variables . The motion of

2173-408: The object must be to make its observed absolute velocity appear with the observed angular motion. Measurements made by viewing the position of some marker relative to something to be measured are subject to parallax error if the marker is some distance away from the object of measurement and not viewed from the correct position. For example, if measuring the distance between two ticks on a line with

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2226-414: The passenger seat, the needle may appear to show a slightly different speed due to the angle of viewing combined with the displacement of the needle from the plane of the numerical dial. Because the eyes of humans and other animals are in different positions on the head, they present different views simultaneously. This is the basis of stereopsis , the process by which the brain exploits the parallax due to

2279-448: The postal service to photograph electricity meters. The M3 was supplemented by the M2 with a 0.72× viewfinder more suited to wide-angle lenses. The next model was the rangefinder-less M1 , intended as an interface with scientific instruments or with a visoflex. With the exception of the larger Leica M5 , subsequent Leica M-series cameras have a strong family resemblance to the M3. In 2002,

2332-457: The principle of parallax. Here, the term parallax is the semi-angle of inclination between two sight-lines to the star, as observed when Earth is on opposite sides of the Sun in its orbit. These distances form the lowest rung of what is called "the cosmic distance ladder ", the first in a succession of methods by which astronomers determine the distances to celestial objects, serving as a basis for other distance measurements in astronomy forming

2385-416: The resultant apparent "floating" movements of the reticle over the target image when the user moves his/her head/eye laterally (up/down or left/right) behind the sight, i.e. an error where the reticle does not stay aligned with the user's optical axis . Some firearm scopes are equipped with a parallax compensation mechanism, which consists of a movable optical element that enables the optical system to shift

2438-568: The reticle image in exact relationship to the eye position in the cylindrical column of light created by the collimating optics. Firearm sights, such as some red dot sights , try to correct for this via not focusing the reticle at infinity, but instead at some finite distance, a designed target range where the reticle will show very little movement due to parallax. Some manufacturers market reflector sight models they call "parallax free", but this refers to an optical system that compensates for off axis spherical aberration , an optical error induced by

2491-460: The reticle is not coincident with the focal plane of the target image. This is because when the reticle and the target are not at the same focus, the optically corresponded distances being projected through the eyepiece are also different, and the user's eye will register the difference in parallaxes between the reticle and the target (whenever eye position changes) as a relative displacement on top of each other. The term parallax shift refers to

2544-458: The spherical mirror used in the sight that can cause the reticle position to diverge off the sight's optical axis with change in eye position. Because of the positioning of field or naval artillery , each gun has a slightly different perspective of the target relative to the location of the fire-control system . When aiming guns at the target, the fire control system must compensate for parallax to assure that fire from each gun converges on

2597-536: The target. Several of Mark Renn 's sculptural works play with parallax, appearing abstract until viewed from a specific angle. One such sculpture is The Darwin Gate (pictured) in Shrewsbury , England, which from a certain angle appears to form a dome, according to Historic England , in "the form of a Saxon helmet with a Norman window... inspired by features of St Mary's Church which was attended by Charles Darwin as

2650-411: The user avoid this problem, the scale is sometimes printed above a narrow strip of mirror , and the user's eye is positioned so that the pointer obscures its reflection, guaranteeing that the user's line of sight is perpendicular to the mirror and therefore to the scale. The same effect alters the speed read on a car's speedometer by a driver in front of it and a passenger off to the side, values read from

2703-578: Was built, sold at auction in 2009 for €72,000. In June 2019 a pre series model from 1952/1953 was sold for €360.000 at the 34th Leitz auction in Wetzlar. This new bayonet mount, which has not been changed in the following half century, is called the Leica M-mount . Lenses are changed faster than with a screw mount, and framelines set automatically. Non-Leitz/Leica bayonet-mount lenses can also be used (although none were produced in any quantity while

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2756-463: Was followed by the still simpler Leica M1 and then the Leica M4 , which used a similar rangefinder design but re-introduced the M3 style frame counter and added a faster loading system and a canted rewind lever. On the present-day used market the M2, originally intended to be more "affordable", sells at prices only slightly lower than the M3. Both cameras are made to a similar level of quality, and

2809-443: Was the first Leica to combine rangefinder and viewfinder into one window. (Other cameras, such as the Contax II , already had this feature before World War II ; and other companies were making screwmount bodies with combined finders.) Framelines for 50, 90 and 135mm are shown, although none for any wider lenses. However, Leica solved this problem in two different ways: The 50 mm framelines are always visible. The viewfinder image

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