Loupe

A loupe (/ˈluːp/ LOOP) is a simple, small magnification device used to see small details more closely. Unlike a magnifying glass, a loupe does not have an attached handle, and its focusing lens(es) are contained in an opaque cylinder or cone or fold into an enclosing housing that protects the lenses when not in use. Loupes are also called hand lenses.

Magnifying glass 20101113
A loupe

Optics

Magnification power of a loupe
Diagram of a single lens loupe

Three basic types of loupes exist:

  • Simple lenses, generally used for low-magnification designs because of high optical aberration.
  • Compound lenses, generally used for higher magnifications to control optical aberration.
  • Prismatic, multiple lenses with prisms.

Uses

Loupes are used in a number of industries, notably the jewelry trade, watchmaking, photography, printing, dentistry, education and ophthalmology. Loupes are also used in academia and life sciences, such as geology and biology. Amateur naturalists may also find a hand lens or a loupe a useful tool when looking at or identifying species. They are also used in numismatics and stamp collecting.

Jewelers and gemologists

BelOMO 10× achromatic triplet loupe 1
BelOMO 10× achromatic triplet jewellers' loupe

Jewelers typically use a monocular, handheld loupe in order to magnify gemstones and other jewelry that they wish to inspect.[1] A 10× magnification is good to use for inspecting jewelry and hallmarks[1] and is the Gemological Institute of America's standard for grading diamond clarity. Stones will sometimes be inspected at higher magnifications than 10×, although the depth of field, which is the area in focus, becomes too small to be instructive.[2] The accepted standard for grading diamonds is therefore that inclusions and blemishes visible at 10× impact the clarity grade.[3]

Watchmaking

Loupes are employed to assist watchmakers in assembling mechanical watches. Many aspects require the use of the loupe, in particular the assembly of the watch mechanism itself, the assembly and details of the watch dial, as well as the formation of the watch strap and installation of precious stones onto the watch face. Some families like Kruder which were into watchmaking and working with glass started producing high-quality loupes in addition to their watches

Photography

Analog (film) photographers use loupes to review, edit or analyze negatives and slides on a light table. Typical magnifications for viewing slides full-frame depend on image format; 35 mm frames (24×36 mm slides to 38×38 mm superslides) are best viewed at ca. 5×, while ca. 3× is optimal for viewing medium format slides (6×4.5 cm / 6×6 cm / 6×7 cm). Often, a 10× loupe is used to examine critical sharpness. Photographers using large format cameras also use a loupe to view the ground glass image to aid in focusing. DSLR camera users also use loupes to help to identify dust and other particles on the sensor, in preparation for sensor cleaning.

Printing

Comptefilsperso
Foldable printers, or linen testers

Offset and flexographic printing see frequent use of loupes in order to carefully analyze how ink lies on paper. Strippers use loupes in order to register film separations to one another. Pressmen use them to check registration of colors, estimate dot-gain, and diagnose issues with roller pressure and chemistry based on the shape of individual dots and rosettes.

Dentistry

Dental loupes aid dentists, hygienists, and dental therapists to devise accurate diagnoses of oral conditions and enhance surgical precision when completing treatment. Additionally, loupes can improve dentists' posture which can decrease occupational strain.[4]

Dental caries, also known as cavities, are most accurately identified by visual and tactile examination of a clean, dry tooth.[5] Magnification enables dentists to improve their ability to differentiate between a stain and a cavity. Cavities are rated and scored based on their visual presentation.[6] If magnification is too high diagnosis becomes difficult due to the small field of view. Ideal magnification for diagnostic purposes is up to 2×.[7][8] Treatment of dental caries, periodontal disease, and pulpal disease are all aided by magnification.

The dental specialty of endodontics has performed the vast majority of research regarding magnification in dentistry. Because the identification of accessory canals in addition to the primary pulp canals is essential to complete nonsurgical root canal therapy, magnification provides dentists enhanced visualization to locate and treat more obscured canals.

Treatment of periodontal disease is achieved by removing calculus deposits, plaque and therefore bacteria which causes inflammation and subsequently bone destruction. In severe cases, surgery to reduce pocket depth is indicated. Periodontists and hygienists must visualize plaque and calculus to remove it. Magnification can assist dentists and hygienists with identification and removal of plaque and calculus in addition to improving visualization for periodontal surgery.[9]

Smallest loupe light
A pair of dental loupes featuring in-lens magnification. There is a loupe light mounted on the bridge of the loupes and side shields (not shown) on the temples to protect a dentist's eyes from splatter.

As dental professionals use both hands in performing dental procedures, dental loupes are binocular and usually take the form of a pair of glasses. Some dental loupes are flip-type, which take the form of two small cylinders, one in front of each lens of the glasses. Other types are inset within the lens of the glasses. A typical magnification for use in dentistry is 2.5×, but dental loupes can be anywhere in the range from 2× to 8×.

Together with proper access to the oral cavity, light is an important part of performing precision dentistry. Because a dentist's head often eclipses the overhead dental lamp, loupes may be fitted with a light source. Loupe-mounted lights used to be fed by fiber optic cables that connected to either a wall-mounted or table-top light source. Newer models feature a more convenient LED lamp within the loupe-mounted light and an electric cord coming from either the conventional wall-mounted or table-top light source or a belt clip rechargeable battery pack. Options for loupe-mounted cameras and video recorders are also available.[10]

Surgery

Cardiac surgeon wearing loupes
Cardiac surgeon wearing surgical loupes

Surgeons in many specialties commonly use loupes when doing surgery on delicate structures. The loupes used by surgeons are mounted in the lenses of glasses and are custom made for the individual surgeon, taking into account their corrected vision, interpupillary distance and desired focal distance. Multiple magnification powers are available. They are most commonly used in otolaryngology, neurosurgery, plastic surgery, cardiac surgery, orthopedic surgery, and vascular surgery.

Geology

LoupeEZ
Loupe used by a geologist

The loupe (hand lens) is a vital geological field tool used to identify small mineral crystals and structures in rocks.

Biology

Loupes are used by professional and amateur field biologists for help identifying species in field situations where a full-sized microscope is impractical, but the ability to observe small morphological characteristics is desired. Many floras and diagnostic keys for identifying plant or animal species recommend the use of a loupe, because taxa may be separated by minute details like the presence of hairs, shapes of hairs and glands.

Meteoritics

Scientists in the meteoritics and planetary science field as well as private collectors of meteorites use loupes as one of their primary tools in meteorite classification and study, and also for simple examination in the field during meteorite recovery.

Electronics

Due to the extremely small size of many modern surface-mount components used in compact electronics, engineers often use a loupe to inspect the completed circuit board for manufacturing defects such as solder bridging and missing or misaligned components. While soldering or reworking surface-mount components by hand a loupe can be used for identifying and aligning parts. Due to the ever-decreasing size of electronic components, magnification is increasingly required for circuit assembly.

Tattooing

Tattoo artists use loupes to inspect the quality of their needle tips. They do this to ensure the least amount of damage possible to the skin surface.

Numismatists and coin collectors

Loupes are an essential tool in both numismatics, the study of currency, and the related practice of coin collection. Coin collectors frequently employ loupes for better evaluation of the quality of their coins, since identifying surface wear is vital when attempting to classify the grade of a coin. Uncirculated coins (coins without wear) can command a substantial premium over coins with slight wear. This wear cannot always be seen with the naked eye. Numismatists can also employ loupes to identify some counterfeit coins that would pass a naked-eye visual inspection.

Philatelists and stamp collectors

Stamp collectors employ loupes to improve their ability to evaluate the quality of their stamps. Identifying surface, adhesive, and perforation is vital when attempting to classify the grade of a stamp. Mint stamps (stamps without cancellations) with no wear can command a substantial premium over mint stamps with slight wear. This wear cannot always be seen with the naked eye. Practitioners of philately, the study of postage and revenue stamps, also employ loupes to identify counterfeit stamps that would pass naked-eye inspections.

Sharpening

Sharpeners of knives or other edged or pointed tools may use a loupe to inspect the tool and ensure correct angle, straightness of the bevel, a sharp edge and/or point, and a polished finish.

See also

References

  1. ^ a b "Jewelry - How to Use a Loupe - Using Jewelry Magnifiers". Jewelry.About.com
  2. ^ "10X Loupe for Gemologists and Jewelers". International Gem Society.
  3. ^ "The 4C's Of Diamonds: Diamond Clarity". Leibish & Co.
  4. ^ Friedman, Mark J. (2004-01-01). "Magnification in a restorative dental practice: from loupes to microscopes". Compendium of Continuing Education in Dentistry (Jamesburg, N.J.: 1995). 25 (1): 48, 50, 53–55. ISSN 1548-8578. PMID 15645879.
  5. ^ "Diagnosis of Occlusal Caries: Part I. Conventional Methods". www.cda-adc.ca. Retrieved 2016-05-17.
  6. ^ "ICCMS Caries Management" (PDF). www.icdas.org. ICDAS. Retrieved 17 May 2016.
  7. ^ Neuhaus, K. W.; Jost, F.; Perrin, P.; Lussi, A. (2015-12-01). "Impact of different magnification levels on visual caries detection with ICDAS". Journal of Dentistry. 43 (12): 1559–1564. doi:10.1016/j.jdent.2015.09.002. ISSN 1879-176X. PMID 26366524.
  8. ^ Sisodia, Neha; Manjunath, M.K. (2014-08-01). "Impact of Low Level Magnification on Incipient Occlusal Caries Diagnosis and Treatment Decision Making". Journal of Clinical and Diagnostic Research. 8 (8): ZC32–ZC35. doi:10.7860/JCDR/2014/8533.4742. ISSN 2249-782X. PMC 4190790. PMID 25302264.
  9. ^ Hayes, Mj; Taylor, Ja; Smith, Dr (2015-02-17). "Introducing loupes to clinical practice: dental hygienists experiences and opinions". International Journal of Dental Hygiene. 14: 226–30. doi:10.1111/idh.12128. ISSN 1601-5037. PMID 25690424.
  10. ^ "Futudent HD Camera".
2010 Paris–Tours

The 2010 Paris–Tours was the 104th edition of this single day road bicycle racing event and is organized by the Amaury Sport Organisation (ASO), which also runs the Tour de France. Óscar Freire won the Ruban Jaune as he broke the record for the fastest average speed in a professional cycling race or stage longer than 200 km in 2010 Paris–Tours. Taking advantage of a favourable wind over a new shortened course of 233 kilometres (145 mi), he covered the distance in 4 hours 52 minutes 54 seconds at an average speed of 47.730 kilometres per hour (29.658 mph).

Achromatic lens

An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus on the same plane.

The most common type of achromat is the achromatic doublet, which is composed of two individual lenses made from glasses with different amounts of dispersion. Typically, one element is a negative (concave) element made out of flint glass such as F2, which has relatively high dispersion, and the other is a positive (convex) element made of crown glass such as BK7, which has lower dispersion. The lens elements are mounted next to each other, often cemented together, and shaped so that the chromatic aberration of one is counterbalanced by that of the other.

In the most common type (shown), the positive power of the crown lens element is not quite equalled by the negative power of the flint lens element. Together they form a weak positive lens that will bring two different wavelengths of light to a common focus. Negative doublets, in which the negative-power element predominates, are also made.

Andrew Loupe

Andrew Gravolet Loupe (born November 22, 1988) is an American professional golfer who plays on the PGA Tour.

Coddington magnifier

A Coddington magnifier is a magnifying glass consisting of a single very thick lens with a central deep groove diaphragm at the equator, thus limiting the rays to those close to the axis, which again minimizes spherical aberration. This allows for greater magnification than a conventional magnifying glass, typically 10× up to 20×. Most single lens magnifiers are limited to 5× or so before significant distortion occurs. The drawback is that the diaphragm groove reduces the area seen through the magnifier.

Diamond clarity

Diamond clarity is the quality of diamonds that relates to the existence and visual appearance of internal characteristics of a diamond called inclusions, and surface defects, called blemishes. Clarity is one of the four Cs of diamond grading, the others being carat, color, and cut.

Inclusions are solids, liquids, or gases that were trapped in a mineral as it formed. They may be crystals of a foreign material or even another diamond crystal, or may have produced structural imperfections, such as tiny cracks that make a diamond appear whitish or cloudy. The number, size, color, relative location, orientation, and visibility of inclusions can all affect the relative clarity of a diamond. A clarity grade is assigned based on the overall appearance of the stone under ten times magnification, which is a magnification standard for loupes used in the gem world.

Most inclusions present in gem-quality diamonds do not affect the diamonds' performance or structural integrity and are not visible to the naked eyes. However, large clouds can affect a diamond's ability to transmit and scatter light. Large cracks close to or breaking the surface may reduce a diamond's resistance to fracture.

Diamonds with higher clarity grades are more valued, with the exceedingly rare "Flawless" graded diamond fetching the highest price. Minor inclusions or blemishes are useful, as they can be used as unique identifying marks analogous to fingerprints. In addition, as synthetic diamond technology improves and distinguishing between natural and synthetic diamonds becomes more difficult, inclusions or blemishes can be used as proof of natural origin.

Jacques Tarride

Jacques Tarride (10 March 1903 – 5 October 1994) was a French actor. He was the son of the actor Abel Tarride and the brother of the director Jean Tarride.

He was born in the 8th arrondissement of Paris and died in La Loupe, Eure-et-Loir.

Jennifer Trask

Jennifer Trask (born 1970, Cape Cod, Massachusetts) is an American artist. She received a BFA in Metalsmithing from the Massachusetts College of Art, and an MFA from the State University of New York at New Paltz.Her work is made from natural materials such as animal bones, antlers, and insect wings.She is known for her wearable jewelry that is reminiscent of Art Nouveau/Rococo styles.Her work has been displayed at Smithsonian American Art Museum, Museum of Arts and Design, The Museum of Fine Arts, Houston, Lisa Sette Gallery, and Gallery Loupe.

John H. Foley

Sergeant John H. Foley (1839 – November 18, 1874) was an Irish-born soldier in the U.S. Army who served with the 3rd U.S. Cavalry during the Indian Wars. He was one of four men received the Medal of Honor for gallantry in leading an attack against the Sioux Indians near Loupe Fork of the Platte River in Nebraska on April 26, 1872.

La Loupe

La Loupe is a commune in the Eure-et-Loir department in northern France.

Leroy H. Vokes

Leroy H. Vokes (November 12, 1849 – June 11, 1924) was an American soldier in the U.S. Army who served with the 3rd U.S. Cavalry during the Indian Wars. A veteran of campaigns against the Plains Indians, he was one of four men who received the Medal of Honor for "gallantry in action" against hostile Indians at the Loupe Fork of the Platte River in Nebraska on April 26, 1872.

Loupe (surname)

Loupe is a locational surname of French origin, which originally meant a person from Loupes or La Loupe in France. The name may refer to:

Andrew Loupe (born 1988), American golfer

Loupe light

Loupe lights are used in conjunction with loupes. They are mainly used in the fields of medicine, dentistry and jewelry.

Because loupes magnify a small field of vision, the amount of light that is focused into through the loupe is less than what is seen by just the naked eye. The dimness experienced is negligible for a nonprofessional user, but for professionals who require accuracy and precision and work in a confined area like dentistry, a loupe light provides illumination that will dramatically increase the level of detail he/she can see through loupes.

Paris–Brest railway

The railway from Paris to Brest is a 622-kilometre long railway line in France that connects Paris and the western port city Brest, via Le Mans and Rennes. It is used for passenger (express, regional and suburban) and freight traffic.

The railway was opened in several stages between 1840 and 1865.

Pocket comparator

A Pocket comparator is an optical device for measuring and inspection comprising a loupe and a reticle. The instrument was developed and manufactured by the Bell & Howell Company, but similar instruments of other names are made by other manufacturers.

It is used for:

Linear measurements in fractions of an inch.

Circular measurements in fractions of an inch.

Radius measurements.

Angle measurements.

Narrow line width measurements.

Circular measurements in decimals of an inch.

Linear measurements in inches.

Linear measurements in millimetersMeasurements are performed by bringing the surface of the reticle as close as possible to the work inspected.

Sarine (company)

Sarine Technologies Ltd is a publicly-traded company that develops, produces and sells technologies for the diamond industry, including devices for the planning, analysis and grading of rough and polished diamonds. Company headquarters are located in Hod Hasharon, Israel. The company operates subsidiaries in Dalton, Israel, India, New York and Hong Kong. In 2017, Sarin India, the Indian subsidiary, opened “Sarin House” in Surat, consolidating the company’s Surat-based activities in one facility.The company is publicly traded on the Singapore stock exchange (SGX) and was the first Israeli company to be listed there. In 2018, Sarine opened the Sarine Technology Lab at the Israel Diamond Exchange, and later that year opened a lab in Mumbai, India. The Sarine labs are the first diamond laboratories in the world to use diamond grading technologies based on artificial intelligence.

Screw It!

Screw It! is Danger Danger's second full-length album. It was released on October 1, 1991 on Epic Records. The album was recorded at New River Studios in Fort Lauderdale, Florida. This is the same studio that the band Skid Row used to record their second album, Slave to the Grind.

Space Needle

The Space Needle is an observation tower in Seattle, Washington, a landmark of the Pacific Northwest and an icon of Seattle. It was built in the Seattle Center for the 1962 World's Fair, which drew over 2.3 million visitors. Nearly 20,000 people a day used its elevators.Once the tallest structure west of the Mississippi River, it is 605 ft (184 m) high, 138 ft (42 m) wide, and weighs 9,550 short tons (8,660 tonnes). It is built to withstand winds of up to 200 mph (320 km/h) and earthquakes of up to 9.0 magnitude, as strong as the 1700 Cascadia earthquake. It also has 25 lightning rods.The Space Needle has an observation deck at 520 ft (160 m) and the rotating SkyCity restaurant at 500 ft (150 m). The downtown Seattle skyline, as well as the Olympic and Cascade Mountains, Mount Rainier, Mount Baker, Elliott Bay and surrounding islands can be viewed from the top of the Needle. Photographs of the Seattle skyline often show the Space Needle prominently, above skyscrapers and Mount Rainier.Visitors can reach the top of the Space Needle by elevators that travel at 10 mph (16 km/h). The trip takes 41 seconds. On windy days, the elevators slow to 5 mph (8.0 km/h). On April 19, 1999, the city's Landmarks Preservation Board designated it a historic landmark.In September 2017, the restaurant was temporarily closed as part of a US$100 million renovation. The renovation included the installation of a new rotation motor and see-through glass floors in the restaurant, as well as the replacement of the observation deck's wire enclosure with glass panels. As of November 2018, the restaurant is still closed with an announcement on its reopening date expected before January 2019. In August 2018, it unveiled its latest addition: the world's first and only revolving glass floor, known as "The Loupe." Standing 500 feet -- or 50 stories -- above street level, the observation deck's new see-through floor offers 360-degree views of the large city. The floor is powered by 12 motors and is constructed of 10 layers of tightly bonded glass to ensure safety.

William H. Strayer

Private William H. Strayer (born 1847, date of death unknown) was an American soldier in the U.S. Army who served with the 3rd U.S. Cavalry during the Indian Wars in Nebraska. He was one of four men, along with Sergeant John H. Foley, First Sergeant Leroy Vokes and civilian scout William F. "Buffalo Bill" Cody, awarded the Medal of Honor for gallantry in action against a Miniconjou Sioux raiding party at the Loupe Fork of the Platte River on April 26, 1872.

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