Binoculars and Police uniforms and equipment in the United Kingdom: Difference between pages

Revision as of 02:46, 9 December 2005

Revision as of 10:15, 29 June 2007

Line 1:

{{Lead section|date=May 2007}}

[[Image:Navy binoculars.jpg|200px|thumb|right|U.S. Navy binoculars]]

[[Image:Bins08sm.JPG|100px|thumb|right|Binoculars]]

'''Binocular telescopes''' or '''binoculars''' are two identical or [[mirror]]-[[symmetry|symmetrical]] [[telescope]]s mounted side-by-side and aligned to point accurately in the same direction, one to be viewed through each of the user's eyes. By contrast, relatively small single-tube telescopes are often called "monoculars".

==Uniform==

The advantages of a binocular over a monocular telescope are:

[[Image:Hampshire helmet constable.jpg|thumb|right|A Hampshire Constabulary custodian ("bobby") helmet]]

*it gives a 3-dimensional [[image]] with depth: the two distinct views presented from slightly different viewpoints to each of the viewer's eyes merge to produce a single perceived view with a sensation of depth, allowing distances to be estimated

[[Image:Edinburgh G8 police group DSC05042.JPG|thumb|right|Police officers in white shirt and helmets]]

*it is more comfortable to use both eyes for viewing, without the need to close or obstruct one eye to avoid confusion

[[Image:Police.three.on.patrol.london.arp.jpg|thumb|right|Metropolitan Police officers wearing hi-visibility jackets]]

*it is easier and more comfortable to steadily hand-hold and move a pair of binoculars than a single tube—the two hands and the head form a steady 3-point platform.

Although there are minor variations in the styling, pattern and [[insignia]], the police forces of [[Great Britain]], [[Jersey]], [[Guernsey]], the [[Isle of Man]] and [[Gibraltar]] all wear very similar [[uniform]]s. In general, these have taken their lead from the [[Metropolitan Police]], with changes appearing in that force first. The base colour is a very dark blue, almost indistinguishable from black (and these days often actually is black), which earnt the police the nickname of the "boys in blue".

Formal uniform comprises an open-necked [[tunic]] (with or without an attached [[belt (clothing)|belt]], depending on the force) and [[trousers]] or [[skirt]], worn with a white or light blue [[shirt]] and black [[necktie|tie]] (usually [[Clip-on tie|clip-on]], so it cannot be used to strangle the wearer). Although most forces once wore blue shirts, these have been less used since the [[1980s]] (when the Metropolitan Police changed to white) and most now wear white. Officers of the rank of [[inspector]] and above have always worn white shirts, and in many forces so have female officers. In some forces, female officers wear a black and white checked [[cravat]] instead of a tie. Officers of the rank of [[Sergeant]] and above wear rank badges on their epaulettes, while [[Constables]] and Sergeants also wear "[[collar number]]s" on them.

The most commonly seen binoculars are of a size to be held by hand, and contain optical elements to fold the optical path so that the physical length of the binoculars is less than the [[focal length]] of the [[lens]]es. The folding of the [[optical path]] allows the separation between the [[objective lens]]es to be increased, allowing larger lenses to be used and giving a better sensation of depth.

Until the mid 1990s this was also the everyday working uniform, but today it is rarely seen except on formal occasions. The normal working dress retains the shirt (open-necked or with a tie or cravat) and trousers, worn with or without a [[jersey (clothing)|jersey]] or [[fleece (clothing)|fleece]]. Some forces use [[combat trousers]] and [[combat boot|boots]]. Today, female officers almost never wear a skirt in working dress, and frequently wear trousers in formal dress as well. Officers also frequently wear reflective waterproof [[jacket]]s, which have replaced the old [[overcoat|greatcoat]]s and [[cloak]]s traditionally worn in inclement weather. Most officers now wear [[body armour]] when on duty.

All practical binoculars display an [[erect image]], obtained either by using simple [[Galilean optics]] ("[[field glasses]]", "[[opera glasses]]"), or by using [[optical prism]]s both to erect the image and to fold the optical path.

Basic headgear is a [[Combination Cap|peaked cap]] for men, and a round [[bowler hat|bowler]] style hat for women. All officers wear a black and white (red and white for the [[City of London Police]]) diced band around the hat, a distinction first used in Scotland and later adopted by all forces in Great Britain. Traffic officers wear white cap covers (yellow in Derbyshire). On foot duty, male constables and sergeants outside [[Scotland]] wear the familiar conical [[custodian helmet]]. There are several patterns, with different forces wearing different types. Although some Scottish forces have used helmets in the past, they are no longer worn in Scotland.

Larger binoculars become uncomfortable and difficult to hold steady, and are mounted on [[tripod]]s or other supports. Very large binoculars with a very wide separation (up to 15 meters, weight 10 tonnes, for ranging [[World War II|Second World War]] naval gun targets 25km away) have been used for accurate [[rangefinding]], although late twentieth century technology made this application redundant.

Officers of the [[Police Service of Northern Ireland]] (PSNI) wear a uniform which is somewhat different, due to the political situation. The main colour to be found is a dark and light green with the uniform looking very unlike mainland police uniforms.

An extreme example, although not one would that normally be called binoculars, is the Large Binocular Telescope in Arizona, USA, which produced its "First Light" image on 26 October 2005. The LBT comprises two 8-meter reflector telescopes. While not intended to be held to the eyes of a viewer (!), the use of two telescopes to view the same object gives additional information due to the separation of the objective mirrors.

===Uniform history===

The first uniform, which was a lighter blue than at present, was a high-collared [[tailcoat]], worn with white trousers in summer. The headgear was a hardened [[top hat]], which served the dual purpose of protecting the officer from blows to the head and allowing him to use it as a step to climb or see over walls. The sleeves of the dark blue coats originally had a pattern of white bars, roughly 6 mm wide by 50 mm high, set roughly 6 mm apart. This immediately distinguished them from naval or maritime personnel. Although this feature was taken up in the [[Dominion]]s, it was not used in the USA.

The tailcoat was later replaced by a tunic, still high-collared, and the top hat by the [[custodian helmet]] (both adopted by the Metropolitan Police in 1863). With a few exceptions (including the [[City of London Police]] and the [[Hampshire Constabulary]]), the helmet plate was (and still is) based on the [[Brunswick star]]. The helmet itself was of cork faced with fabric. The design varied slightly between forces. Some had that favoured by the Metropolitan Police, topped with a boss, others had a helmet that incorporated a ridge or crest terminating above the badge, while others had a short spike, sometimes topped with a ball.

==Prismatic binoculars==

Binoculars with prisms to shorten the optical path and erect the image may have [[Porro prism|double Porro prism]] design which gives a Z-shaped optical path. This results in a set of binoculars which is wide, with objective lenses which are well-separated but offset from the [[eyepiece]]s. Binoculars which use [[roof prism|roof prisms]] (either the [[Abbe-Koenig prism|Abbe-Koenig]] or [[Schmidt-Pechan prism|Schmidt-Pechan]] designs) are narrower, more compact, lighter, and more expensive than those which use Porro prisms. They have objective lenses which are approximately in line with the eyepieces.

The tunic went through many lengths and styles, with the Metropolitan Police adopting the open-neck style in 1948 (although senior and female officers adopted it before that time). Senior officers used to wear peaked pillbox-style caps until the adoption of the wider peaked cap worn today.

==Design details==

Binoculars to be used to view objects which are not at a fixed distance must have a [[focussing]] arrangement. In some cases the two telescopes are focused independently by changing the distance between ocular and objective lenses. It is more convenient for the viewer to focus both tubes with one action (usually rotation of a central focussing wheel), and for one of the two eyepieces to be adjustable to compensate for differences between the viewer's eyes (usually by rotating the eyepiece in its mount). Once this adjustment has been made for a given viewer, the binoculars can be refocussed on an object at a different distance by using the focussing wheel to move both tubes together without eyepiece readjustment.

Female officers' uniforms have gone through a great variety of styles, as they have tended to reflect the women's fashions of the time. Tunic style, skirt length and headgear have varied by period and force. By the late 1980s, female working uniform was virtually identical to male, except for headgear and sometimes neckwear.

The distance between the eyepieces on most binoculars can be adjusted to accommodate viewers with different eye separation.

==Personal radios==

[[image:binocular-optics.png|thumb|250px|left|Optical layout of a binocular with a double-Porro design]]

In 2004, British police forces began the roll-out of a digital [[TETRA]] (Terrestrial Trunked Radio) system for communications, called [[Airwave (communications network)|Airwave]]. The Airwave system replaced the previous Motorola radio handsets and [[two-way radio]]s with a mobile phone-like device, which is supposed to improve radio coverage, is encrypted to prevent interception, and allows data as well as voice transmission. The roll-out is due for complete coverage of all UK police forces and other emergency services by the end of 2007.

Personal radio systems were first issued to police officers and installed in police cars in the 1960s (resulting in the demise of the "[[police box]]" telephones made famous by ''[[Doctor Who]]''). From the 1990s, officers frequently carried [[mobile phone]]s in addition to their personal radio units.

==Optical parameters==

The diameter of the objective lenses determines the light-gathering power and the ultimate [[resolving power]] of the binoculars. The ratio of the focal lengths of the objective and the ocular lenses gives the linear magnifying power (expressed in "diameters"). It is customary to categorise binoculars by the magnification × the objective diameter in mm; e.g. 7×50.

==Firearms and weapons==<!-- This section is linked from [[The Adventures of Tintin]] -->

The magnification required depends upon the application, but with the major proviso that large magnifications give an image much more susceptible to shake when hand-held. The objective lens needs to be large enough to give acceptable resolution in all circumstances, but must be larger for low-light and night use.

In the [[United Kingdom]] and some other countries of the [[Policing in the United Kingdom|British police]] tradition, the police are not normally issued firearms, but are issued other weapons ([[Club (weapon)#Telescopic batons|batons]], [[pepper spray]], [[CS spray]] etc.), although some officers may be issued firearms in special situations. This originates from the formation of the [[Metropolitan Police]] in the [[19th Century]], when police were not armed, partly to counter public fears and objections concerning armed enforcers. However, the [[Ministry of Defence Police]], [[Civil Nuclear Constabulary]] and [[Police Service of Northern Ireland]] (formerly the [[Royal Ulster Constabulary]]) are issued firearms as a matter of routine. Every force can also call upon armed response units in a matter of minutes, and certain specialist squads, such as the [[Flying Squad]], [[Special Branch]], [[Diplomatic Protection Group]], Royalty Protection Branch, and officers protecting airports and government buildings, are routinely armed.

The weapons carried routinely by ordinary police constables are currently an extending [[Club (weapon)|baton]] and, in all but two county police services, personal issue [[Riot control agent|incapacitant spray]], such as CS (a chemical incapacitant) or CapTor (a natural incapacitant based on extracts from [[Capsicum]] peppers. The effects of sprays are designed to be short-lived, subsiding within 30-60 minutes and clearing more quickly in well-ventilated areas.

The [[field of view]] depends upon the optical construction of the binoculars. Simple Galilean binoculars have the disadvantage of a narrower field of view&mdash;this is the reason for the prevalence of the more complex optical arrangements used.

The use of batons varies across the country and each force selects which baton is best able to fulfil its needs and provide the best protection to officers. Friction lock batons such as the [http://www.asp-net.com/ ASP] are popular, although the PR-24 [[Monadnock]] extendable baton (sometimes known as the side-handled baton) or the Monadnock Straight Lock baton is used in some forces. Some forces use a one piece "Arnold" baton, although they are relatively rare except in forces in the North of England.

For general hand-held use, subject to shake, 7 diameters is a good compromise between power and image steadiness for most people. 7×30 is good for daytime use. For general night use, a 50mm objective gives maximum brightness for 7 diameters magnification; objective diameter must be increased for higher magnifications at night.

===Use of firearms===

Hand-held binoculars range from small 3x10 Galilean [[opera glasses]] used in [[theater]]s, to glasses with 7 to 12 diameters magnification and 30 to 50mm objectives for typical outdoor use. Larger models with objectives of up to about 120mm are used on supports, typically for amateur astronomy. Much larger binoculars have been made by dedicated amateur astronomers, essentially using two refracting or reflecting astronomical telescopes, with results claimed to be impressive.

[[Image:Police armed uk.jpg|thumb|right|Firearms officers wearing body armour]]

Unlike the police in most other countries, most officers in the British police are not routinely armed, except in [[Northern Ireland]], at [[airport]]s, [[nuclear power plant|nuclear facilities]], and on some protection duties. However every territorial police force has an armed contingent of officers patrolling able to support unarmed colleagues when required. The arming of the police is a perennial topic of debate.

Officers on night patrols in some [[London]] divisions were frequently armed with [[Webley and Scott|Webley]] [[revolver]]s (and, after the [[Sidney Street Siege|Battle of Stepney]], Webley [[semi-automatic self-loading pistol|semi-automatics]]) for over 50 years following the [[murder]] of two officers in [[1884]], though individual officers were able to choose whether to carry the weapons. The practice ended in July [[1936]], after which arms could be issued by a sergeant if there was a ''good reason'', and if the officer had been trained.

Of particular relevance for low-light and astronomical viewing, as against astrophotography, is the [[ratio]] between magnifying power and objective lens diameter. Binoculars concentrate the light gathered by the objective into a beam, the [[exit pupil]] whose diameter is the objective diameter divided by the magnifying power. For maximum effective light-gathering and brightest image, the exit pupil should equal the diameter of the fully dilated human eye&mdash;about 7mm, reducing with age. Light gathered by a larger exit pupil is wasted. However, for viewing stars and small astronomical objects, a large exit pupil will mostly image the night sky background, effectively decreasing contrast, making the detection of faint objects more difficult except perhaps in remote locations with negligible [[light pollution]]. A large exit pupil facilitates viewing larger objects such as nearby galaxies, though. The current trend favours models with 5mm exit pupil, such as 10x50, or 8x40; 7x50 is falling out of favour. For daytime use an exit pupil of 3mm&mdash;matching the eye's contracted pupil&mdash;is sufficient.

The issue of routine arming was next raised after the [[1952]] [[Derek Bentley]] case, and again after the 1966 murder of three officers in London ([[Massacre of Braybrook Street]]), following which around 17% of officers in London were authorised to carry firearms. After the deaths of a number of members of the public in the [[1980s]], control was considerably tightened, many officers had their firearm authorisation revoked, and training for the remainder was greatly improved and later extended to include some training from the [[Special Air Service|SAS]].{{Fact|date=February 2007}} Currently around seven per cent of officers in London are trained in the use of firearms. Firearms are also only issued to an officer under strict guidelines <ref>[http://www.acpo.police.uk/asp/policies/Data/firearms.pdf ACPO firearms policy]</ref> See [[Specialist Firearms Command|CO19]] (Metropolitan Police Firearms Unit).

==Optical construction==

When light strikes an interface between two materials of different [[refractive index]] (e.g., at an air-glass interface), some of the light is [[transmitted]], some [[reflected]]. In any sort of image-forming optical instrument (telescope, camera, microscope, etc.), ideally no light should be reflected; instead of forming an image, light which reaches the viewer after being reflected is distributed in the field of view, and reduces the contrast between the true image and the background. Reflection can be reduced, but not eliminated, by applying optical coatings to interfaces; this is of great importance for any optical instrument with multiple interfaces. Light can also be reflected from the interior of the instrument, but it is simple to minimise this to negligible proportions.

In order to allow armed officers to rapidly attend an incident most forces have patrolling [[Armed Response Vehicle]]s (ARVs). ARVs were modelled on the Instant Response Cars introduced by the [[West Yorkshire Police]] in [[1976]], and were first introduced in London in [[1991]], when 132 armed deployments were made. Today [[CO19]] and the [[Diplomatic Protection Group]] provide London with ARVs with officers having weapons permanently holstered on their person to allow rapid deployment.

Phase-corrected prism coating and dielectric prism coating are recent (in 2005) effective techniques for reducing reflections.

Although largely attributable to a significant increase{{fact|June 2007}} in the use of imitation firearms and air weapons, the overall increase in firearms crime between 1998/99 and 2002/03{{fact|June 2007}} (it has been decreasing since 2003/04, although use of imitations continued to rise){{fact|June 2007}} has kept this issue in the spotlight. For the first time since 1936, the routine carrying of firearms on normal police patrols was re-introduced in [[Nottingham]] in February [[2000]], in response to a number of gang related shootings on the St Ann's and Meadows estates. Despite this, [[Police Federation of England and Wales|Police Federation]] surveys have continued to show overwhelming police officer resistance to routine arming. In the Federation's most recent (2006) Officer/Arming survey, 82% of respondents were against the routine arming of police.<ref>[http://www.polfed.org/WhereWeStand_Firearms_and_the_policeAWAITING_INFO230506.pdf Police Federation Survey]</ref>

When light traverses an optically transmissive material, some light is absorbed. This reduces brightness, and is also undesirable, although less of a problem than reflections in most cases. (The advanced naval binocular rangefinders of the mid-twentieth century had perhaps 150 glass elements; absorption of light would have been significant.)

As of September [[2004]], all forces in England and Wales also have the [[Taser]] available, but it may only be used by Firearms Officers, although there have been growing calls quietly from within the ranks and the public for all officers to be routinely armed with a [[Taser]]. The [[Police Federation]] have already called for this and is a firm position held by it. <ref>[http://www.polfed.org/we_stand_F0AE5868581B4E239F2FEDFC4D976359.asp Police Federation]</ref>

Different optical construction affects reflections and brightness. A [[Porro prism]] binocular will inherently produce an intrinsically brighter image than a roof [[Prism (optics)|prism]] binocular of the same magnification, objective size, and optical quality, as less light is absorbed along the optical path. However, as of 2005, the optical quality of the best roof-prism binoculars with up-to-date coating processes as used in Schmidt-Pechan models is comparable with the best Porro glasses, and it appears that roof prisms will dominate the market for high-quality portable binoculars in spite of their higher price. The major European optical manufacturers (Leica, Zeiss, Swarovski) have discontinued their Porro lines; Japanese manufacturers (Nikon, Fujinon, etc.) may follow suit.

<small>''For more on firearm use by British police, see the [[Policing in the United Kingdom#Controversial shootings|controversial shootings section]] of the main [[Policing in the United Kingdom]] article.''</small>

When buying binoculars of lower price, Porro prism binoculars can be expected to give more image quality for money.

[[Image:PolicingAnimalRightsDemonstrationOxford20050129 CopyrightKaihsuTai.JPG|thumb|right|250px|[[Thames Valley Police]] policing an animal rights demonstration in Oxford]]

==Image stabilisation==

Shake can be much reduced, and higher magnifications used, with binoculars using [[image stabilisation]] technology. Parts of the instrument which change the position of the image may be held steady by powered [[gyroscopes]] or by powered mechanisms driven by gyroscopic or inertial detectors, or may be mounted in such a way as to oppose and dampen sudden movement. Stabilisation may be enabled or disabled by the user as required. These techniques allow binoculars up to 20× to be hand-held, and much improve the image stability of lower-power instruments. There are some disadvantages: the image may not be quite as good as the best unstabilised binoculars when tripod-mounted, and stabilised binoculars contain more advanced technology to go wrong, and to become obsolete. They are also more expensive, heavier, and battery life tends to be short.

Stabilisation is not suitable when tracking moving objects.

==MaintenancePolice vehicles==

{{main|Police Car}}

If the binoculars are not ''collimated'' properly, i.e., if the images from the two tubes are not properly aligned, then they will give poor results and can be uncomfortable and tiring to use. This may be due to poor manufacturing quality control (more likely with cheaper binoculars) or to a shock (being dropped) or drift over time. If the binoculars are basically sound, this can be remedied by small movements to the prisms, often by turning screws accessible without opening the binoculars. While it is inadvisable for the non-expert to try to repair quality instruments, collimation by the owner may be justified for maladjusted binoculars which are not good enough to merit the expense of professional attention. Instructions for checking binoculars for collimation errors, and for collimating them, can be found on the Internet (search for ''collimation binoculars'' and the model).

The archetypal British "bobby" walked his beat alone. Apart from rapid response units, motor vehicles were rarely used except in rural districts (and even there, [[bicycle]]s were more common). However, following the 1964 [[Police Act 1964|Police Act]], the police became increasingly motorised and it is now rare to see an officer on foot patrol except in city or town centres, and then rarely alone. More recently, police forces have begun to put officers back on the beat as 'community' or 'neighbourhood' patrols. In an increasing number of urban centres police bicycle units are used to provide a quick response in congested areas, pedestrianised areas and parkland, as well as carrying out patrols. A bicycle patrol provides a happy balance between the distance covered by a motorised patrol and the approachability of the foot patrol. <ref>[http://www.tfl.gov.uk/tfl/press-centre/press-releases/press-releases-content.asp?prID=298 TFL 999 London Cycling Award press release]</ref> The [[Metropolitan Police]] now have over 1500 police bicycles.<ref>[http://www.daveches.co.uk/analysis/bikes Police on bikes, from LS8]</ref>

[[Image:UK Police Battenburg.jpg|thumb|right|Traffic Police Car with high visibility battenburg markings.]]

A well-collimated pair of binoculars should produce, when viewed through human eyes and processed by a human brain, a single circular, apparently three-dimensional, image, with no visible indication that we are actually viewing two distinct images from slightly different viewpoints. Departure from the ideal causes, at best, vague discomfort and visual fatigue, but the perceived field of view will be close to circular anyway. The cinematic convention to represent a view through binoculars as two circles partially overlapping in a figure-of-eight shape is not true to life.

[[Police car|Patrol cars]], sometimes known as [[panda car]]s, are in use everywhere and may be crewed by one or two officers. In Scotland, because of the necessity of corroborating evidence, there are always two officers in a vehicle. Rapid response vehicles are utilised for various departments in each police force. Some examples are: armed response vehicles and some traffic department vehicles, which come in marked and unmarked variations. Typical examples of high-powered rapid response vehicles are BMW 5 series, Volvo T5s and V70s, enhanced [[Opel Vectra|Vauxhall Vectra]]s and various Subaru and Audi high-end models. Police also use Land Rover and Range Rover models - such as for responding to motorway incidents - Jaguar cars are even used by some forces. Most forces use [[Ford Transit]] vans or similar models as personnel carriers, with specially adapted versions in use by public order units such as the Metropolitan Police [[Territorial Support Group]]. Police motorcycles, bicycles and horses are also employed depending on the situation.

All Home Office police forces have access to air support, often in the form of helicopters. Some forces, such as Hampshire, also have small fixed wing aircraft.

==Choosing binoculars==

Ideally a pair of binoculars will produce two uniformly sharp images, each of perfect quality, with no errors of geometry or colour-correction and no internal reflections. The two images will be identical (apart from the slightly different viewpoint), with no differences in size, orientation, aberrations, etc. Real binoculars depart to a greater or lesser extent from the ideal.

Forces with significant waterways to police maintain police watercraft, ranging from [[Zodiac Group|Zodiac]] dinghies to [[Arun class lifeboat|ARUN class]] boats.<ref>[http://www.met.police.uk/msu/training.htm Metropolitan Police Marine Unit]</ref><ref>[http://www.strathclyde.police.uk/index.asp?locID=927&docID=-1 Strathclyde Police Marine Policing Unit]</ref>

All binoculars should be accurately aligned and [[collimated]], comfortable to use, and robust. Roof-prism models will be lighter and more compact for a given size, but more expensive than equivalent Porro models.

==Other relevant pages==

Hermetically sealed binoculars filled with dry gas (usually nitrogen) will not be susceptible to clouding due to condensation at low temperatures; this will also help to prevent [[mildew]], although air may leak in over a period of years if the binoculars are not overhauled. Completely waterproof (submersible) binoculars are available.

* [[Police Aviation in United Kingdom]]

==References==

All binoculars should be reasonably free from reflections. Fully multi-coated (FMC) models should be better in this respect than others. For roof-prism models, phase coating is better.

{{reflist}}

[[Category:Law enforcement in the United Kingdom]]

The magnification and objective diameter must be chosen to suit the requirement, remembering that higher magnification exaggerates shake when hand-held, and that larger objective lenses increase the weight and size.

[[Category:Law enforcement equipment|British police]]

For general-purpose use, 8x40 is a good combination. 7x50 is brighter for night use. Larger objective diameters have better light-gathering power, and can view fainter objects for astronomical use. If more compact binoculars are required, smaller objectives may be used at some loss of performance and increase in price.

Image stabilisation much improves image steadiness and allows the use of higher magnification in hand-held applications. The trade-off is that compared to unstabilised binoculars of the same parameters, stabilised binoculars are more expensive, larger and heavier, less reliable due to their complexity, more subject to obsolescence, and consume batteries.

Zoom binoculars, while in principle a good idea, do not perform very well.

Some binoculars (and cameras) claim to be "focus-free". This is an example of marketing departments making a virtue of necessity. Such models would have been called "fixed-focus" in more honest times: they have a depth of field from a relatively large closest distance, to infinity, and perform exactly the same as a focussing model of the same optical quality (or lack of it) focussed on the middle distance.

Binoculars of the same make and model may vary from unit to unit, although hopefully less so for the more highly priced models from quality manufacturers, so the experienced user may benefit from trying several samples. By the same token, many cheaper types of generally mediocre quality but basically sound design may have a few exceptionally good units.

Some reputable binocular manufacturers as of 2005:

'''1. European Brands'''

* Leica GmbH (Ultravid, Duovid, Geovid: all are Roof)

* Swarovski Optik (SLC, EL: all are Roof; Habicht: Porro, but to be discontinued)

* Zeiss GmbH (FL,Victory, Conquest: all are Roof; 7x50 BGAT/T, 15x60 BGA/T:Porro, but to be discontinued)

* Docter Optik (Nobilem: Porro)

* Optolyth (Royal: Roof; Alpin: Porro)

* Steiner (Commander, Nighthunter: Porro; Predator, Wildlife: Roof)

'''2. Japanese Brands'''

* Canon Co. (I.S. series, Porro variants?)

* Nikon Co. (High Grade series, Monarch series,RAII, Spotter series: Roof; Prostar series, Superior E series, E series, Action EX series: Porro)

* Fujinon Co. (FMTSX, MTSX series: Porro)

* Kowa Co. (BD series: Roof)

* Pentax Co. (DCFSP/XP series; Roof, UCF series: Inverted Porro; PCFV/WP/XCF series: Porro)

* OLympus Co. (EXWPI series: Roof)

* Minolta Co. (Activa, some are Roof, some are Porro)

* Vixen Co. (Apex/Apex Pro: Roof; Ultima: Porro)

* Miyauchi Co. (Specialized in over-sized Porro binocualars)

P.S. Many of the above are [[OEM]] products of Kamakura or Chinese manufacturing plants.

'''3. Chinese Brands'''

In the early years of the 21st century some mid-priced glasses have become available on the internal Chinese market. A few of them are said to be comparable both in performance and in price to some of the better brands; the great majority of them are inferior.

* Sicong (from Xian Stateoptics. Navigator series: Roof; Ares series: Porro)

* WDtian (from Yunnan State optics, all Porro)

* Yunnan State optics (MS series: Porro)

[[Image:HMAS Melbourne binoculars.jpg|thumb|right|Naval ship binoculars]]

Binoculars are widely used by amateur astronomers, their wide [[field of view]] making them useful for [[comet]] and [[supernova]] seeking (giant binoculars) and general observation (portable binoculars). The major market is amongst bird watchers and hunters, who mostly prefer, and are prepared to pay for, the lighter but more expensive roof-prism models.

==See also==

* [[Monocular]]

* [[Telescope]]

* [[Spotting scope]]

== External links ==

* [http://www.opticsplanet.com/info/how_to_buy_binoculars.shtml Understanding binoculars]

[[Category:Optical devices]]

[[de:Fernglas]]

[[es:Prismáticos]]

[[fa:دوربین شکاری]]

[[fr:Jumelles]]

[[id:Binokular]]

[[it:Binocolo]]

[[nl:Verrekijker]]

[[nds:Kieker (Optik)]]

[[ja:双眼鏡]]

[[pl:Lorneta]]

[[ru:Бинокль]]

[[sk:Ďalekohľad]]

[[sv:Kikare]]

[[th:กล้องสองตา]]