Tripod

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Young George Washington using a surveyor's tripod Young George Washington.jpg
Young George Washington using a surveyor's tripod

A tripod is a portable three-legged frame or stand, used as a platform for supporting the weight and maintaining the stability of some other object. A tripod provides stability against downward forces and horizontal forces and movements about horizontal axes. The positioning of the three legs away from the vertical centre allows the tripod better leverage for resisting lateral forces.

Contents

Etymology

First attested in English in the early 17th century, the word tripod comes via Latin tripodis ( GEN of tripus), [1] [2] which is the romanization of Greek τρίπους (tripous), "three-footed" (GENτρίποδος, tripodos), [3] ultimately from τρι- (tri-), "three times" [4] (from τρία, tria, "three") [5] + πούς (pous), "foot". [6] The earliest attested form of the word is the Mycenaean Greek 𐀴𐀪𐀠, ti-ri-po, written in Linear B syllabic script. [7]

Cultural use

A ding from late Shang Dynasty. Liu Ding.jpg
A ding from late Shang Dynasty.

Many cultures, including the ancient peoples of China and Greece, used tripods as ornaments, trophies, sacrificial altars, cooking vessels or cauldrons, and decorative ceramic pottery. Tripod pottery have been part of the archaeological assemblage in China since the earliest Neolithic cultures of Cishan and Peiligang in the 7th and 8th millennium BC. [8] Sacrificial tripods were found in use in ancient China usually cast in bronze but sometimes appearing in ceramic form. [9] They are often referred to as "dings" and usually have three legs, but in some usages have four legs.

The Chinese use sacrificial tripods symbolically in modern times, such as in 2005, when a "National Unity Tripod" made of bronze was presented by the central Chinese government to the government of northwest China's Xinjiang Uygur Autonomous Region to mark its fiftieth birthday. It was described as a traditional Chinese sacrificial vessel symbolizing unity. [10]

In ancient Greece, tripods were frequently used to support lebes, or cauldrons, sometimes for cooking and other uses such as supporting vases.

Firearms

Seabees train with the M240B mounted on the M122 tripod. US Navy 070406-N-0775Y-078 Equipment Operator 1st Class Shannon Farber instructs Mass Communication Specialist 1st Class Carmichael Yepez how to aim a M-240B machine gun during a weapons training exercise at a range in Camp Han.jpg
Seabees train with the M240B mounted on the M122 tripod.

On firearms, tripods are commonly used on machine guns to provide a forward rest and to reduce motion from recoil. Machine guns are capable of firing long continuous bursts of fire, but at the cost of increased recoil (which decreases accuracy), and increased weight (machine guns are heavier in order to absorb the stresses of prolonged fully automatic fire). The tripod permits the operator to rest the weapon on the ground and thus the gun feels lighter to the shooter and accuracy is increased.

Tripods are generally restricted to heavier weapons where the weight would be an encumbrance. For lighter weapons such as rifles, a bipod is more common.

Photography

Usage

A tripod used to support a rooftop television antenna TV antenna tripod.JPG
A tripod used to support a rooftop television antenna

Tripods are used for both motion and still photography to prevent camera movement and provide stability. They are especially necessary when slow-speed exposures are being made, or when telephoto lenses are used, as any camera shake while the shutter is open will produce a blurred image. In the same vein, they reduce camera shake, and thus are instrumental in achieving maximum sharpness. A tripod is also helpful in achieving precise framing of the image, or when more than one image is being made of the same scene, for example when bracketing the exposure. Use of a tripod may also allow for a more thoughtful approach to photography. For these reasons, a tripod of some sort is often necessary for professional photography. In relation to film/video, use of the tripod offers stability within a shot as well as certain desired heights. The use of a tripod within film/video is often a creative choice of the Director.

Construction

Tripod for offshore wind turbine Cuxhaven 67 (RaBoe).jpg
Tripod for offshore wind turbine

For maximum strength and stability, as well as for easy levelling, most photographic tripods are braced around collapsible telescopic legs, with a center post that moves up and down. To further allow extension, the center post can usually extend above the meeting of three legs. At the top of the tripod is the head, which includes the camera mount (usually a detachable plate with a thumbscrew to hold the camera). The head connects to the frame by several joints, allowing the camera to pan, tilt and roll. The head usually attaches to a lever so that adjustments to the orientation can be performed more delicately. Some tripods also feature integrated remote controls for a camera, though these are usually proprietary to the company that manufactured the camera.

Surveying

A surveyor's tripod is a device used to support any one of a number of surveying instruments, such as theodolites, total stations, levels or transits.

Usage

The tripod is placed in the location where it is needed. The surveyor will press down on the legs' platforms to securely anchor the legs in soil or to force the feet to a low position on the uneven, pockmarked pavement. Leg lengths are adjusted to bring the tripod head to a convenient height and make it roughly level.

Once the tripod is positioned and secure, the instrument is placed on the head. The mounting screw is pushed up under the instrument to engage the instrument's base and screwed tight when the instrument is in the correct position. The flat surface of the tripod head is called the footplate and is used to support the adjustable feet of the instrument.

Positioning the tripod and instrument precisely over an indicated mark on the ground or benchmark requires techniques that are beyond the scope of this article.

Tripods have also been used in the industry of film and photography since it's invention was made to provide easier long exposure images for photographic studios.

Construction

Many modern tripods are constructed of aluminum, though wood is still used for legs. The feet are either aluminum tipped with a steel point or steel. The mounting screw is often brass or brass and plastic. The mounting screw is hollow to allow the optical plumb to be viewed through the screw. The top is typically threaded with a 5/8" x 11 tpi screw thread. The mounting screw is held to the underside of the tripod head by a movable arm. This permits the screw to be moved anywhere within the head's opening. The legs are attached to the head with adjustable screws that are usually kept tight enough to allow the legs to be moved with a bit of resistance. The legs are two part, with the lower part capable of telescoping to adjust the length of the leg to suit the terrain. Aluminum or steel slip joints with a tightening screw are at the bottom of the upper leg to hold the bottom part in place and fix the length. A shoulder strap is often affixed to the tripod to allow for ease of carrying the equipment over areas to be surveyed.

Astronomy

The astronomical tripod is a sturdy three-leg stand used to support telescopes or binoculars, though they may also be used to support attached cameras or ancillary equipment. The astronomical tripod is normally fitted with an altazimuth or equatorial mount to assist in tracking celestial bodies. [11] [12]

Laboratory

Laboratory Tripod Laboratory tripod.jpg
Laboratory Tripod

Laboratory tripod is a portable, three-legged platform equipment, which is usually made of lightweight metal such as stainless steel or aluminium so that it can be moved conveniently within the lab. The main usage is to support or hold the flasks and beakers during experiments.

See also

Related Research Articles

Linear B Syllabic script that was used for writing Mycenaean Greek

Linear B is a syllabic script that was used for writing Mycenaean Greek, the earliest attested form of Greek. The script predates the Greek alphabet by several centuries. The oldest Mycenaean writing dates to about 1450 BC. It is descended from the older Linear A, an undeciphered earlier script used for writing the Minoan language, as is the later Cypriot syllabary, which also recorded Greek. Linear B, found mainly in the palace archives at Knossos, Cydonia, Pylos, Thebes and Mycenae, disappeared with the fall of Mycenaean civilization during the Late Bronze Age collapse. The succeeding period, known as the Greek Dark Ages, provides no evidence of the use of writing. It is also the only one of the Bronze Age Aegean scripts to have been deciphered, by English architect and self-taught linguist Michael Ventris.

Theodolite Optical surveying instrument

A theodolite is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but they are also used extensively for building and infrastructure construction, and some specialized applications such as meteorology and rocket launching.

Grip (job)

In the United States, Canada and the United Kingdom, grips are technicians in the filmmaking and video production industries. They constitute their own department on a film set and are directed by a key grip. Grips have two main functions. The first is to work closely with the camera department to provide camera support, especially if the camera is mounted to a dolly, crane, or in an unusual position, such as the top of a ladder. Some grips may specialize in operating camera dollies or camera cranes. The second main function of grips is to work closely with the electrical department to create lighting set-ups necessary for a shot under the direction of the director of photography.

Grips' responsibility is to build and maintain all the equipment that supports cameras. This equipment, which includes tripods, dollies, tracks, jibs, cranes, and static rigs, is constructed of delicate yet heavy duty parts requiring a high level of experience to operate and move. Every scene in a feature film is shot using one or more cameras, each mounted on highly complex, extremely expensive, heavy duty equipment. Grips assemble this equipment according to meticulous specifications and push, pull, mount or hang it from a variety of settings. The equipment can be as basic as a tripod standing on a studio floor, to hazardous operations such as mounting a camera on a 100 ft crane, or hanging it from a helicopter swooping above a mountain range.

Good Grips perform a crucial role in ensuring that the artifice of film is maintained, and that camera moves are as seamless as possible. Grips are usually requested by the DoP or the camera operator. Although the work is physically demanding and the hours are long, the work can be very rewarding. Many Grips work on both commercials and features.

Mycenaean Greek Most ancient attested form of the Greek language from the 16th to 12th centuries BC

Mycenaean Greek is the most ancient attested form of the Greek language, on the Greek mainland and Crete in Mycenaean Greece, before the hypothesised Dorian invasion, often cited as the terminus ad quem for the introduction of the Greek language to Greece. The language is preserved in inscriptions in Linear B, a script first attested on Crete before the 14th century BC. Most inscriptions are on clay tablets found in Knossos, in central Crete, as well as in Pylos, in the southwest of the Peloponnese. Other tablets have been found at Mycenae itself, Tiryns and Thebes and at Chania, in Western Crete. The language is named after Mycenae, one of the major centres of Mycenaean Greece.

Xiphos Iron Age weapon

The xiphos is a double-edged, one-handed Iron Age straight shortsword used by the ancient Greeks. It was a secondary battlefield weapon for the Greek armies after the dory or javelin. The classic blade was generally about 45–60 cm (18–24 in) long, although the Spartans supposedly preferred to use blades as short as 30 cm (12 in) around the era of the Greco-Persian Wars. The xiphos sometimes has a midrib, and is diamond or lenticular in cross-section. It was a rather light weapon, with a weight around 450 to 900 grams or 1-2 lbs. It was generally hung from a baldric under the left arm. The xiphos was generally used only when the spear was broken, taken by the enemy, or discarded for close combat. Very few xiphe are known to have survived.

Levelling

Levelling or leveling is a branch of surveying, the object of which is to establish or verify or measure the height of specified points relative to a datum. It is widely used in geodesy and cartography to measure geodetic height, and in construction to measure height differences of construction artifacts. It is also known as spirit levelling and differential levelling.

Monopod

A monopod, also called a unipod, is a single staff or pole used to help support cameras, binoculars, rifles or other precision instruments in the field.

Tripod (photography)

In photography, a tripod is used to stabilize and elevate a camera, a flash unit, or other photographic equipment. All photographic tripods have three legs and a mounting head to couple with a camera. The mounting head usually includes a thumbscrew that mates to a female threaded receptacle on the camera, as well as a mechanism to be able to rotate and tilt the camera when it is mounted on the tripod. Tripod legs are usually made to telescope, in order to save space when not in use. Tripods are usually made from aluminum, carbon fiber, steel, wood or plastic.

Tribrach (instrument)

A tribrach is an attachment plate used to attach a surveying instrument, for example a theodolite, total station, GNSS antenna or target to a tripod. A tribrach allows the survey instrument to be repeatedly placed in the same position over a surveying marker point with sub-millimetre precision, by loosening and re-tightening a lock to adjust the instrument base in a horizontal plane.

Level (instrument)

A level is an optical instrument used to establish or verify points in the same horizontal plane in a process known as levelling, and is used in conjunction with a levelling staff to establish the relative heights levels of objects or marks. It is widely used in surveying and construction to measure height differences and to transfer, measure, and set heights of known objects or marks.

Meridian circle

The meridian circle is an instrument for timing of the passage of stars across the local meridian, an event known as a culmination, while at the same time measuring their angular distance from the nadir. These are special purpose telescopes mounted so as to allow pointing only in the meridian, the great circle through the north point of the horizon, the north celestial pole, the zenith, the south point of the horizon, the south celestial pole, and the nadir. Meridian telescopes rely on the rotation of the sky to bring objects into their field of view and are mounted on a fixed, horizontal, east–west axis.

Potnia

Potnia is an Ancient Greek word for "Mistress, Lady" and a title of a goddess. The word was inherited by Classical Greek from Mycenean Greek with the same meaning and it was applied to several goddesses. A similar word is the title Despoina, "the mistress", which was given to the nameless chthonic goddess of the mysteries of Arcadian cult. She was later conflated with Kore (Persephone), "the maid", the goddess of the Eleusinian mysteries, in a life-death rebirth cycle which leads the neophyte from death into life and immortality. Karl Kerenyi identifies Kore with the nameless "Mistress of the labyrinth", who probably presided over the palace of Knossos in Minoan Crete.

Microphone stand

A microphone stand is a free-standing mount for a microphone. It allows the microphone to be positioned in the studio, on stage or on location without requiring a person to hold it.

Hippeia or Hippea is the name of two characters in Greek mythology.

Drum hardware

Drum hardware refers to the parts of a drum or drum kit that are used to tension, position, and otherwise support the instruments themselves.

Tripod (surveying)

A surveyor's tripod is a device used to support any one of a number of surveying instruments, such as theodolites, total stations, levels or transits.

A weapon mount is an assembly or mechanism used to hold a weapon onto a platform in order for it to function at maximum capacity. Weapon mounts can be broken down into two categories: static mounts and non-static mounts.

Tripod head

A tripod head is the part of a tripod system that attaches the supported device to the tripod legs, and allows the orientation of the device to be manipulated or locked down. Modular or stand-alone tripod heads can be used on a wide range of tripods, allowing the user to choose which type of head best suits their needs. Integrated heads are built directly onto the tripod legs, reducing the cost of the tripod system.

Temporary adjustments are a set of operations which are performed on a theodolite to make it ready for taking observations. These include its initial setting up on a tripod or other stand, centering, levelling up and focusing of eyepiece.

References

  1. tripus . Charlton T. Lewis and Charles Short. A Latin Dictionary on Perseus Project .
  2. Harper, Douglas. "tripod". Online Etymology Dictionary .
  3. τρίπους . Liddell, Henry George ; Scott, Robert ; A Greek–English Lexicon at the Perseus Project
  4. τρι-  in Liddell and Scott.
  5. τρία  in Liddell and Scott.
  6. πούς  in Liddell and Scott.
  7. ti-ri-po is found on the PY Ta 641 and PY Ta 709 tablets. 𐀴𐀪𐀠𐀆, ti-ri-po-de (found on the PY Ta 641 tablet), is the NOM dual form of the word. "The Linear B word ti-ri-po-de". Palaeolexicon. Word study tool of ancient languages.Raymoure, K.A. "ti-ri-po". Minoan Linear A & Mycenaean Linear B. Deaditerranean. "PY 641 Ta (2)". "PY 709 Ta (2)". DĀMOS: Database of Mycenaean at Oslo. University of Oslo.
  8. Stark, Miriam T. (2006). Archaeology of Asia. Blackwell Publishing. p. 44. ISBN   978-1-4051-0213-1.CS1 maint: discouraged parameter (link)
  9. Wolfram, Eberhard. "A History of China". Berkeley and Los Angeles: University of California Press, 3rd edition, 1969. Cf. p.49 for illustration of Ancient bronze tripod found at Anyang.
  10. "National Unity Tripod presented to mark Xinjiang's 50th birthday". China: People's Daily. October 1, 2005.
  11. "Telescope and Tripod". Universe Today.
  12. Rotoni, Vito (23 May 2003). "Telescope Support Stand System: Background of the Invention". U.S. Patent and Trademark Office 7048238.