1.
Camera
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Thumb|A2016 Nikon D810 A camera is an optical instrument for recording or capturing images, which may be stored locally, transmitted to another location, or both. The images may be individual still photographs or sequences of images constituting videos or movies, the camera is a remote sensing device as it senses subjects without physical contact. The word camera comes from camera obscura, which means dark chamber and is the Latin name of the device for projecting an image of external reality onto a flat surface. The modern photographic camera evolved from the camera obscura, the functioning of the camera is very similar to the functioning of the human eye. A camera may work with the light of the spectrum or with other portions of the electromagnetic spectrum. A still camera is a device which creates a single image of an object or scene. All cameras use the basic design, light enters an enclosed box through a converging lens/convex lens. A shutter mechanism controls the length of time that light can enter the camera, a display, often a liquid crystal display, permits the user to view scene to be recorded and settings such as ISO speed, exposure, and shutter speed. A movie camera or a video camera operates similarly to a camera, except it records a series of static images in rapid succession. When the images are combined and displayed in order, the illusion of motion is achieved, the forerunner to the photographic camera was the camera obscura. The oldest known record of this principle is a description by Han Chinese philosopher Mozi, Mozi correctly asserted that the camera obscura image is inverted because light travels in straight lines from its source. In the 11th century Arab physicist Ibn al-Haytham s wrote very influential essays about experiments with light through an opening in a darkened room. The use of a lens in the opening of a wall or closed window shutter of a room to project images used as a drawing aid has been traced back to circa 1550. Since the late 17th century portable camera obscura devices in tents, before the development of the photographic camera, it had been known for hundreds of years that some substances, such as silver salts, darkened when exposed to sunlight. The first person to use this chemistry to create images was Thomas Wedgwood, to create images, Wedgwood placed items, such as leaves and insect wings, on ceramic pots coated with silver nitrate, and exposed the set-up to light. These images werent permanent, however, as Wedgwood didnt employ a fixing mechanism and he ultimately failed at his goal of using the process to create fixed images created by a camera obscura. The first permanent photograph of an image was made in 1826 by Joseph Nicéphore Niépce using a sliding wooden box camera made by Charles. Niépce had been experimenting with ways to fix the images of a camera obscura since 1816, the photograph Niépce succeeded in creating shows the view from his window
2.
Binoculars
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Binoculars or field glasses are two telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes when viewing distant objects. Most are sized to be held using both hands, although sizes vary widely from opera glasses to large pedestal mounted military models. Almost from the invention of the telescope in the 17th century the advantages of mounting two of them side by side for binocular vision seems to have been explored, most early binoculars used Galilean optics, that is, they used a convex objective and a concave eyepiece lens. The Galilean design has the advantage of presenting an image but has a narrow field of view and is not capable of very high magnification. This type of construction is used in very cheap models. They also have large exit pupils making centering less critical and the field of view works well in those applications. These are typically mounted on a frame or custom-fit onto eyeglasses. An improved image and higher magnification is achieved in binoculars employing Keplerian optics, since the Keplerian configuration produces an inverted image, different methods were used to turn the image right way up. In aprismatic binoculars with Keplerian optics each tube has one or two additional lenses between the objective and the ocular and these lenses are used to erect the image. The binoculars with erecting lenses have a disadvantage, their length is too long. Such binoculars were popular in the 1800s, but became obsolete shortly after the Karl Zeiss company introduced improved prism binoculars in the 1890s, Optical prisms added to the design are another way to turn the image right way up, usually in a Porro prism or roof-prisms design. Porro prism binoculars are named after Italian optician Ignazio Porro who patented this image erecting system in 1854, Binoculars of this type use a Porro prism in a double prism Z-shaped configuration to erect the image. This feature results in binoculars that are wide, with lenses that are well separated. Thus, the size of binoculars is reduced, Binoculars using roof prisms may have appeared as early as the 1870s in a design by Achille Victor Emile Daubresse. Most roof prism binoculars use either the Abbe-Koenig prism or the Schmidt-Pechan prism designs to erect the image and they have objective lenses that are approximately in line with the eyepieces. Roof-prisms designs create an instrument that is narrower and more compact than Porro prisms, there is also a difference in image brightness. Roof-prisms designs also require tighter tolerances for alignment of their optical elements and this adds to their expense since the design requires them to use fixed elements that need to be set at a high degree of collimation at the factory. Porro prisms binoculars occasionally need their prism sets to be re-aligned to bring them into collimation, the fixed alignment in roof-prism designs means the binoculars normally will not need re-collimation
3.
Shutter speed
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The amount of light that reaches the film or image sensor is proportional to the exposure time. 1/500th of a second will let half as much light in as 1/250th, the cameras shutter speed, the lenss aperture, and the scenes luminance together determine the amount of light that reaches the film or sensor. Exposure value is a quantity that accounts for the shutter speed and this will achieve a good exposure when all the details of the scene are legible on the photograph. Too much light let into the results in an overly pale image while too little light will result in an overly dark image. Multiple combinations of speed and f-number can give the same exposure value. According to exposure value formula, doubling the exposure time doubles the amount of light, for example, f/8 lets 4 times more light into the camera as f/16 does. In addition to its effect on exposure, the speed changes the way movement appears in photographs. Very short shutter speeds can be used to freeze fast-moving subjects, very long shutter speeds are used to intentionally blur a moving subject for effect. Short exposure times are called fast, and long exposure times slow. Adjustments to the aperture need to be compensated by changes of the speed to keep the same exposure. The agreed standards for shutter speeds are, With this scale, camera shutters often include one or two other settings for making very long exposures, B keeps the shutter open as long as the shutter release is held. T keeps the open until the shutter release is pressed again. The ability of the photographer to take images without noticeable blurring by camera movement is an important parameter in the choice of the slowest possible speed for a handheld camera. Through practice and special techniques such as bracing the camera, arms, or body to minimize movement, using a monopod or a tripod. If a shutter speed is too slow for hand holding, a support, usually a tripod. Image stabilization on digital cameras or lenses can often permit the use of shutter speeds 3–4 stops slower, Shutter priority refers to a shooting mode used in cameras. It allows the photographer to choose a shutter speed setting and allow the camera to decide the correct aperture and this is sometimes referred to as Shutter Speed Priority Auto Exposure, or TV mode, S mode on Nikons and most other brands. Shutter speed is one of methods used to control the amount of light recorded by the cameras digital sensor or film
4.
Focal length
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The focal length of an optical system is a measure of how strongly the system converges or diverges light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus. A system with a focal length has greater optical power than one with a long focal length. For a thin lens in air, the length is the distance from the center of the lens to the principal foci of the lens. For a converging lens, the length is positive, and is the distance at which a beam of collimated light will be focused to a single spot. For a diverging lens, the length is negative, and is the distance to the point from which a collimated beam appears to be diverging after passing through the lens. The focal length of a lens can be easily measured by using it to form an image of a distant light source on a screen. The lens is moved until an image is formed on the screen. In this case 1/u is negligible, and the length is then given by f ≈ v. Back focal length or back focal distance is the distance from the vertex of the last optical surface of the system to the focal point. For an optical system in air, the focal length gives the distance from the front. If the surrounding medium is not air, then the distance is multiplied by the index of the medium. Some authors call these distances the front/rear focal lengths, distinguishing them from the front/rear focal distances, defined above. In general, the length or EFL is the value that describes the ability of the optical system to focus light. The other parameters are used in determining where an image will be formed for an object position. The quantity 1/f is also known as the power of the lens. The corresponding front focal distance is, FFD = f, in the sign convention used here, the value of R1 will be positive if the first lens surface is convex, and negative if it is concave. The value of R2 is negative if the surface is convex
5.
Camera lens
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A lens might be permanently fixed to a camera, or it might be interchangeable with lenses of different focal lengths, apertures, and other properties. While in principle a simple convex lens will suffice, in practice a compound made up of a number of optical lens elements is required to correct the many optical aberrations that arise. Some aberrations will be present in any lens system and it is the job of the lens designer to balance these and produce a design that is suitable for photographic use and possibly mass production. Typical rectilinear lenses can be thought of as improved pinhole lenses, as shown, a pinhole lens is simply a small aperture that blocks most rays of light, ideally selecting one ray to the object for each point on the image sensor. Here a pixel is the area of the detector exposed to light from a point on the object, making the pinhole smaller improves resolution, but reduces the amount of light captured. At a certain point, shrinking the hole does not improve the resolution because of the diffraction limit, beyond this limit, making the hole smaller makes the image blurrier as well as darker. Practical lenses can be thought of as an answer to the question how can a pinhole lens be modified to more light. A first step is to put a simple convex lens at the pinhole with a length equal to the distance to the film plane. The geometry is almost the same as with a pinhole lens. From the front of the camera, the hole, would be seen. If one were inside the camera, one would see the acting as a projector. The virtual image of the aperture from inside the camera is the exit pupil. Practical photographic lenses include more lens elements, a camera lens may be made from a number of elements, from one, as in the Box Brownies meniscus lens, to over 20 in the more complex zooms. These elements may themselves comprise a group of lenses cemented together, the front element is critical to the performance of the whole assembly. In all modern lenses the surface is coated to reduce abrasion, flare, and surface reflectance, to minimize aberration, the curvature is usually set so that the angle of incidence and the angle of refraction are equal. In a prime lens this is easy, but in a zoom there is always a compromise, the lens usually is focused by adjusting the distance from the lens assembly to the image plane, or by moving elements of the lens assembly. To improve performance, some lenses have a cam system that adjusts the distance between the groups as the lens is focused, manufacturers call this different things, Nikon calls it CRC, Canon calls it a floating system, and Hasselblad and Mamiya call it FLE. Glass is the most common used to construct lens elements, due to its good optical properties
6.
Tripod (photography)
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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 head to couple with a camera. Tripod legs are made to telescope, in order to save space when not in use. Tripods are usually made from aluminum, carbon fiber, steel, tripods are used for both still and motion photography to prevent camera movement. They are necessary when slow-speed exposures are being made, or when lenses of extreme focal length are used, 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, use of a tripod may also allow for a more thoughtful approach to photography. For all of reasons, a tripod of some sort is often necessary for professional photography as well as certain video uses. Tripods are also used as an alternative to C-Stands to photographic accessories, for maximum strength and stability, most photographic tripods are braced around a center post, with collapsible telescoping legs and a telescoping section at the top that can be raised or lowered. Some tripods also feature integrated remote controls to control a camcorder or camera, materials used in the construction of tripod or monopod legs include metal, wood and carbon fiber-reinforced plastics, among others. Per ISO1222,2010, the current tripod screw thread standard for attaching the camera calls for a 1/4-20 UNC or 3/8-16 UNC thread, most consumer cameras are fitted with 1/4-20 UNC threads. Larger, professional cameras and lenses may be fitted with 3/8-16 UNC threads, plus a removable 1/4-20 UNC adapter, in this application, the BSW and UNC thread profiles are similar enough that one can mount a modern camera on a legacy tripod and vice versa. The UNC threads are a 60-degree angle and flattened, whereas the BSW are a 55-degree angle, however, at least one English manufacturer uses No.1 B. A. for its tripod mount thread. There are several types of tripods, the least expensive, generally made of aluminum tubing and costing less than US$50, is used primarily for consumer still and video cameras, these generally come with an attached head and rubber feet. The head is very basic, and often not entirely suitable for smooth panning of a camcorder, a common feature, mostly designed for still cameras, allows the head to flip sideways 90 degrees to allow the camera to take pictures in portrait format rather than landscape. Often included is a pin on the front of the mounting screw that is used to stabilize camcorders. This is not found on the more expensive photographic tripods, more expensive tripods are sturdier, stronger, and usually come with no integrated head. The separate heads allow a combination to be customized to the photographers needs. There are expensive carbon fiber tripods, used for applications where the needs to be lightweight
7.
Selfie
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A selfie is a self-portrait photograph, typically taken with a digital camera or camera phone held in the hand or supported by a selfie stick. Selfies are often shared on social networking such as Facebook, Instagram. They are usually flattering and made to appear casual, most selfies are taken with a camera held at arms length or pointed at a mirror, rather than by using a self-timer. A selfie stick can be used to position the camera away from the subject. Robert Cornelius, an American pioneer in photography, produced a daguerreotype of himself in 1839 which is one of the first photographs of a person. Because the process was slow he was able to uncover the lens, run into the shot for a minute or more and he recorded on the back The first light Picture ever taken. The debut of the portable Kodak Brownie box camera in 1900 led to photographic self-portraiture becoming a widespread technique. The method was usually by mirror and stabilizing the camera either on an object or on a tripod while framing via a viewfinder at the top of the box. Grand Duchess Anastasia Nikolaevna of Russia, at the age of 13, was one of the first teenagers to take her own using a mirror to send to a friend in 1914. In the letter that accompanied the photograph, she wrote, I took this picture of myself looking at the mirror and it was very hard as my hands were trembling. This practice transitioned naturally across to digital cameras as they supplanted film cameras around the turn of the millennium, the first known use of the word selfie in any paper or electronic medium appeared in an Australian internet forum on 13 September 2002. In Karl Kruszelnickis Dr Karl Self-Serve Science Forum, a post by Nathan Hope stated, Um, drunk at a mates 21st, I tripped ofer, I had a hole about 1cm long right through my bottom lip. And sorry about the focus, it was a selfie, Hope has dismissed the notion that he coined the term, describing it as something that was just common slang at the time, used to describe a picture of yourself. As early as 2003, Italian media artist Alberto Frigo started photographing every object his right hand uses, the life long project resulted in the first categorized collection of selfies showing the artist every time he brushed his teeth, every time he put on deodorant etc. The Sony Ericsson Z1010 mobile phone, released in late 2003, the Z1010s front-facing camera had a sensor for selfies and video calls. The term selfie was discussed by photographer Jim Krause in 2005, in the early 2000s, before Facebook became the dominant online social network, self-taken photographs were particularly common on MySpace. However, writer Kate Losse recounts that between 2006 and 2009, the MySpace pic became an indication of bad taste for users of the newer Facebook social network, early Facebook portraits, in contrast, were usually well-focused and more formal, taken by others from distance. In 2009 in the hosting and video hosting website Flickr, Flickr users used selfies to describe seemingly endless self-portraits posted by teenage girls
8.
Trekking pole
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Trekking poles are a common hiking accessory used to assist walkers with their rhythm and provide stability on rough terrain. When in use, trekking poles resemble ski poles as they have features in common, such as baskets at the bottom, rubber-padded handles. When fully retracted it may be possible to them to a backpack. Some poles come with spring-loaded sections to aid walking under normal conditions and to reduce wrist strain and they are usually made from lightweight aluminum or carbon fiber. Descendants of the walking stick, trekking poles are usually used by hikers for the same reasons — to provide some rhythm to their walking pace. On flat, smooth terrain they really arent necessary although using them can increase the exercise a hiker gets from the trip, but on less certain terrain, or steep slopes, they provide useful lateral stability, and many turn to them for help with knee pain. They can also be used as aids when climbing rocks or boulders, to probe the depth of mud or water and facilitate a crossing. When traversing steep slopes for long distances, some hikers make one pole shorter than the other to make those trips feel more as if they were taking place on level ground, some backpacking tents are designed to use trekking poles as tent poles. Along the same lines, trekking poles can be used to set up a Bivouac shelter, hikers who take to snowshoes in winter find trekking poles especially useful. They can also be used in Nordic walking in a rural or urban environment, the Appalachian Trail Conservancy estimates that pole usage rates on the Appalachian Trail vary from 90% among thru-hikers to 10–15% among day hikers. Some hikers have complained that pole use can leave an impact on the surrounding trail, for instance poking visible holes in the ground. In particular the most common complaint is that the carbide tips leave visible white scratches on rock, all these can detract from the wilderness experience. The Appalachian Trail Conservancy recommends several measures to mitigate the impact of trekking poles in accordance with Leave No Trace principles of low-impact backcountry recreation. Hikers, it says, should not only be aware of what they put their poles into, they should remove the pole baskets unless hiking in snow and use rubber tips to avoid scratch marks on rocks. On level sections, or in areas where the potential for adverse impact is high, Hiking equipment Hiking Nordic walking Walking stick
9.
Selfie stick
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A selfie stick is a monopod used to take selfie photographs by positioning a smartphone or camera beyond the normal range of the arm. The metal sticks are typically extensible, with a handle on one end, some have remote or Bluetooth controls, letting the user decide when to take the picture, and models designed for cameras have a mirror behind the viewscreen so that the shot can be lined up. Safety concerns and the inconvenience the product causes to others have resulted in them being banned at many venues, including all Disney Parks, homemade selfie sticks could date back as early as 1925. A photo from that shows a man taking a photograph of himself and his wife, with the aid of a long pole which is pointed towards the camera. A device which has been likened to the selfie stick appears in the 1969 Czechoslovak sci-fi film I Killed Einstein, Gentlemen. The 1983 Minolta Disc-7 camera had a mirror on its front to allow the composition of self-portraits. A telescopic extender for compact handheld cameras was patented in U. S. in 1983, canadian inventor Wayne Fromm patented his Quik Pod in 2005 and becoming commercially available in the United States the following year. In 2012, Yeong-Ming Wang filed a patent for a multi-axis omni-directional shooting extender capable of holding a smartphone, the term selfie stick did not become widely used until 2014. Extended forms of sticks can hold laptop computers to take selfies from a webcam. The selfie stick was listed in Time magazines 25 best inventions of 2014, the device gives more practical use in situations that require assistance for difficult photographs. It allows the user to take photographs in dangerous situations such as taking a photo over a cliff or from the door of an airplane. The device is used to take selfies that involve the photographer inside a moving vehicle. Selfie sticks can be triggered by Bluetooth-linked mechanisms, or connections that use the audio jack. The Bluetooth remote shutter is compatible with Android 4.2.2 OS and above, some selfie sticks have telescoping capabilities that allow for greater length and wider shots. Several concert venues in Australia and the United Kingdom have banned the use of selfie sticks, organisers have cited their role in the illegal recording of bands sets, and the inconvenience and safety issues to fellow audience members. The sticks have been banned in some museums, galleries and historical sites because of concerns about damage to artworks. Theme parks including Walt Disney World Resort, Six Flags and Universal Orlando, selfie sticks have been banned from many sporting events both for their nuisance value and for interfering with other spectators enjoyment or view. The Australia Tour Down Under banned the devices citing harm to cyclists, officials, emirates Stadium, home of the Arsenal Football Club, bans any object that could be used as a weapon or could compromise public safety, and regards selfie sticks as such an item
10.
Sako TRG
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Sako TRG-22/42 sniper rifles were developed by the Finnish firearm manufacturer SAKO of Riihimäki. The rifles are available with olive green, desert tan/coyote brown, dark earth or black stocks. Normally muzzle brakes are fitted to reduce recoil, jump and flash, the Sako factory TRG muzzle brakes vent sideways and are detachable. Generally TRGs are outfitted with a Zeiss or Schmidt & Bender PM II telescopic sight with fixed power of magnification or with variable magnification. Variable telescopic sights can be used if the operator more flexibility to shoot at varying ranges. In 1989 Sako Ltd. introduced the TRG-21 precision rifle as a rifle model chambered for the.308 Winchester cartridge. Subsequently, a sniper rifle with a 20 mm longer scaled up magnum action emerged as the TRG-41 in order to take advantage of the.338 Lapua Magnum cartridge. Similarly, a variant of this model, again using the same bolt. Even though the TRG-21 obtained its origins from the successful Sako TR-6 target rifle, the evolution of this design continues to the present and can be found in Sakos most recent hunting rifle offerings, the Sako 75 and the Sako 85. To make the TRG system more suitable for use, Sako upgraded and improved the TRG-21/41 design in the late 1990s. Some TRG accessories like the muzzle brake and bipod were also improved and this resulted in the TRG-22/42 rifle system. Around 2011 an American Sako vendor commissioned a limited production run of TRG-22 rifles chambered for the.260 Remington cartridge. In 2013 the TRG system was upgraded and improved based on customer requirements. Further the bolt handle and its attachment to the body were ruggedized. These general 2013 upgrades are backwards compatible with older TRG rifles, Sako never totally forgot the target rifle origins of the TRG system. The necessary accessories to attach sighting components such as match grade peep sights or target aperture sights, the rifle is commonly seen in long-range competition where it has done very well. Besides civilian target shooting the TRG system can and is used for hunting. The TRG system’s purposive design features, reliability in conditions and consistent accuracy performance have made it a popular, though expensive
11.
Sniper rifle
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A sniper rifle is a man-portable, high precision, shoulder-fired rifle, for military or law enforcement use, designed to ensure more accurate shooting at longer ranges than other small arms. A typical sniper rifle is built for high levels of accuracy, fitted with a telescopic sight, the military role of a sniper dates back to the turn of the 18th century, but the true sniper rifle is a much more recent development. Some sniper rifles are based on the designs of standard rifles, the Whitworth rifle was arguably the first long-range sniper rifle in the world. His rifle was far more accurate than the Pattern 1853 Enfield, at trials in 1857, which tested the accuracy and range of both weapons, Whitworths design outperformed the Enfield at a rate of about three to one. Also, the Whitworth rifle was able to hit the target at a range of 2,000 yards, during the Crimean War, the first optical sights were designed for fitting onto the rifles. Much of this work was the brainchild of Colonel D. Davidson. This allowed a marksman to more accurately observe and target objects at a distance than ever before. The telescopic sight, or scope, was fixed and could not be adjusted. By the 1870s, the perfection of breech loading magazine rifles led to sniper rifles having effective ranges of up to a mile away from its target. During the Boer War, the latest breech-loading rifled guns with magazine, the British were equipped with the Lee–Metford rifle, while the Boers had received the latest Mauser rifles from Germany. In the open terrain of South Africa, the marksman was a component in battle. The Lovat Scouts was a British Army unit formed in 1899 that was renowned for the expert marksmanship, the men wore ghillie suits for camouflage and were expertly skilled in observation. Hesketh Hesketh-Prichard said of them that men never lived. After the Boer War, the Scouts became the first official unit in the British Army. It was not until World War I that sniper rifles began to be used regularly in battle. In Germany, these trained snipers were given rifles with telescopic sights, german gunsmiths fitted the scope above the barrel for optimal accuracy. During the War, the accuracy of the rifle was greatly improved. By the end of World War II snipers were reported to provide reasonable accuracy over 600 m with anything over this range being unpredictable
12.
Tripod
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A tripod is a portable three-legged frame, 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. The earliest attested form of the word is the Mycenaean Greek
