Movie Camera
Camera by jekky
(3512, 'History br Main article History of the camera br Camera obscura br The forerunner to the camera was the camera obscura The camera obscura is an instrument consisting of a darkened chamber or box into which light is admitted through a convex lens forming an image of external objects on a surface of paper or glass etc placed at the focus of the lens The camera obscura was described by the Arabic scientist Ibn al Haytham Alhazen in his Book of Optics 10151021 The actual name of camera obscura was applied by mathematician and astronomer Johannes Kepler in his Ad Vitellionem paralipomena of 1604 He later added a lens and made the apparatus transportable in the form of a tent Irish scientist Robert Boyle and his assistant Robert Hooke developed a portable camera obscura in the 1660s br The first camera that was small and portable enough for practical use was built by Johann Zahn in 1685 though it would be almost 150 years before chemical technology caught up to the point where photography was practical Early photographic cameras were essentially similar to Zahn s model though usually with the addition of sliding boxes for focusing Before each exposure a sensitized plate would be inserted in front of the viewing screen to record the image Jacques Daguerre s popular daguerreotype process utilized copper plates while the calotype process invented by William Fox Talbot recorded images on paper br The first permanent colour photograph taken by James Clerk Maxwell in 1861 br The first permanent photograph was made in 1826 by Joseph Nicphore Nipce using a sliding wooden box camera made by Charles and Vincent Chevalier in Paris Nipce built on a discovery by Johann Heinrich Schultz 1724 a silver and chalk mixture darkens under exposure to light However while this was the birth of photography the camera itself can be traced back much further Before the invention of photography there was no way to preserve the images produced by these cameras apart from manually tracing them br The development of the collodion wet plate process by Frederick Scott Archer in 1850 cut exposure times dramatically but required photographers to prepare and develop their glass plates on the spot usually in a mobile darkroom Despite their complexity the wet plate ambrotype and tintype processes were in widespread use in the latter half of the 19th century Wet plate cameras were little different from previous designs though there were some models such as the sophisticated Dubroni of 1864 where the sensitizing and developing of the plates could be carried out inside the camera itself rather than in a separate darkroom Other cameras were fitted with multiple lenses for making cartes de visite It was during the wet plate era that the use of bellows for focusing became widespread br The first colour photograph was made by Scottish physicist James Clerk Maxwell with the help of English inventor and photographer Thomas Sutton in 1861 br The electronic video camera tube was invented in the 1920s starting a line of development that eventually resulted in digital cameras which largely supplanted film cameras after the turn of the 21st century br Mechanics br Image capture br see also Photographic lens design br 19th century studio camera with bellows for focusing br Traditional cameras capture light onto photographic film or photographic plate Video and digital cameras use electronics usually a charge coupled device CCD or sometimes a CMOS sensor to capture images which can be transferred or stored in tape or computer memory inside the camera for later playback or processing br Cameras that capture many images in sequence are known as movie cameras or as cin cameras in Europe those designed for single images are still cameras However these categories overlap As still cameras are often used to capture moving images in special effects work and modern digital cameras are often able to trivially switch between still and motion recording modes A video camera is a category of movie camera that captures images electronically either using analogue or digital technology br Lens br Main article Photographic lens br Main article Photographic lens design br The lens of a camera captures the light from the subject and brings it to a focus on the film or detector The design and manufacture of the lens is critical to the quality of the photograph being taken The technological revolution in camera design in the 18th century revolutionized optical glass manufacture and lens design with great benefits for modern lens manufacture in a wide range of optical instruments from reading glasses to microscopes Pioneers included Zeiss and Leitz br Focus br Auto focus systems can capture a subject a variety of ways here the focus is on the person s image in the mirror br Due to the optical properties of photographic lenses only objects within a limited range of distances from the camera will be reproduced clearly The process of adjusting this range is known as changing the camera s focus There are various ways of focusing a camera accurately The simplest cameras have fixed focus and use a small aperture and wide angle lens to ensure that everything within a certain range of distance from the lens usually around 3 metres 10 ft to infinity is in reasonable focus Fixed focus cameras are usually inexpensive types such as single use cameras The camera can also have a limited focusing range or scale focus that is indicated on the camera body The user will guess or calculate the distance to the subject and adjust the focus accordingly On some cameras this is indicated by symbols head and shoulders two people standing upright one tree mountains br Rangefinder cameras allow the distance to objects to be measured by means of a coupled parallax unit on top of the camera allowing the focus to be set with accuracy Single lens reflex cameras allow the photographer to determine the focus and composition visually using the objective lens and a moving mirror to project the image onto a ground glass or plastic micro prism screen Twin lens reflex cameras use an objective lens and a focusing lens unit usually identical to the objective lens in a parallel body for composition and focusing View cameras use a ground glass screen which is removed and replaced by either a photographic plate or a reusable holder containing sheet film before exposure Modern cameras often offer autofocus systems to focus the camera automatically by a variety of methods br Exposure control br The size of the aperture and the brightness of the scene controls the amount of light that enters the camera during a period of time and the shutter controls the length of time that the light hits the recording surface Equivalent exposures can be made with a larger aperture and a faster shutter speed or a corresponding smaller aperture and with the shutter speed slowed down br Shutters br Main article Shutter photography br Although a range of different shutter devices have been used during the development of the camera only two types have been widely used and remain in use today br The focal plane shutter operates as close to the film plane as possible and consists of cloth curtains that are pulled across the film plane with a carefully determined gap between the two curtains or consisting of a series of metal plates moving either vertically or horizontally across the film plan As the curtains or blades move at a constant speed exposing the whole film plane can takes much longer than the exposure time For example an exposure of 1 1000 second may be achieved by the shutter curtains moving across the film plane in 1 50th of a second but with the two curtains only separated by 1 20th of the frame width When photographing rapidly moving objects the use of a focal plane shutter can produce some unexpected effects Focal plane shutters are also difficult to synchronise with electronic flash and it is often only possible to use flash at shutter speeds below 1 60th second although in some modern cameras that can be as fast as 1 100second br The Copal shutter or more precisely the in lens shutter is a shutter contained within the lens structure often close to the diaphragm consisting of a number of metal leaves which are maintained under spring tension and which are opened and then closed when the shutter is released The exposure time is determined by the interval between opening and closing In this shutter design the whole film frame is exposed at one time This makes flash synchronisation much simpler as the flash only needs to fire once the shutter is fully open This disadvantage of such shutters is their inability to reliably produce very fast shutter speeds and the additional cost and weight of having to include a shutter mechanism for every lens br Film formats becca like travis br Main article Film formats br A wide range of film and plate formats have been used by cameras In the early history plate sizes were often specific for the make and model of camera although there quickly developed some standardisation for the more popular cameras The introduction of roll film drove the standardisation process still further so that by the 1950s only a few standard roll films were in use These included 120 film providing 8 12 or 16 exposures 220 film providing 16 or 24 exposures 127 film providing 8 exposures principally in Brownie 125 cameras and 35mm film providing 12 20 or 36 exposures or up to 72 exposures in bulk cassettes for the Leica Camera range br For cine cameras 35mm film was the original film format but 16mm film soon followed produced by cutting 35mm in two An early amateur format was 9 5mm Later formats included 8mm film and Super 8 br Camera accessories br There are many accessories to a camera those accessories are mainly for care protection special effects and functions br Lens hood is a device used on the end of a lens to block the sun or other light source in order to prevent glare and lens flare br Lens cover a device used to cover and protect the lens during storage br Lens adapter sometimes called a step ring adapts the lens to other size filters br Flash equipment including light diffuser mount and stand reflector soft box trigger and cord br Care and protection including camera case and cover maintenance tools and screen protector br Large format and Marco equipments there are special equipments used for large or Macro format photography those equipment includes magnifier loupe view finder angle finder focusing rail truck br Battery and charger br Camera designs br Plate camera br The earliest cameras produced in significant numbers used sensitised glass plates and are now termed plate cameras Light entered a lens mounted on a lens board which was separated from the plate by an extendible bellows Many of these cameras had controls to raise or lower the lens and to tilt it forwards or backwards to control perspective Focussing of these plate cameras was by the use of a ground glass screen at the point of focus Because lens design only allowed rather small aperture lenses the image on the ground glass screen was faint and most photographers had a dark cloth to cover their heads to allow focussing and composition to be carried out more easily When focus and composition were satisfactory the ground glass screen was removed and a sensitised plate put in its place protected by a dark slide photography To make the exposure the dark slide was carefully slid out and the shutter opened and then closed and the dark slide replaced In current designs the plate camera is best represented by the view camera br Large format camera br Main article View camera br The large format camera is a direct successor of the early plate cameras and remain in use for high quality photography and for technical architectural and industrial photography There are three common types the monorail camera the field camera and the press camera All use large format sheets of film although there are backs for medium format 120 film available for most systems and have an extensible bellows with the lens and shutter mounted on a lens plate at the front These cameras have a wide range of movements allowing very close control of focus and perspective br Medium format camera br Main article Medium format br The medium format cameras has a film negative size somewhere in between the large format cameras and the smaller 35mm cameras Typically these systems use 120 or 220 film The most common sizes being 6x4 5 160 cm 6x6 cm and 6x7 cm The designs of this kind of camera shows greater variation than their larger brethren Ranging from monorail systems via the classic Hasselblad model with separate backs to smaller rangefinder cameras There are even compact amateur cameras available in this format br Folding camera br The introduction of films enabled the existing designs for plate cameras to be made much smaller and for the base plate to be hinged so that it could be folded up compressing the bellows These designs were very compact and small models were dubbed Vest pocket cameras br Box camera br Main article Box camera br Box cameras were introduced as a budget level camera and had few if any controls The original box Brownie models had a small reflex viewfinder mounted on the top of the camera and had no aperture or focussing controls and just a simple shutter Later models such as the Brownie 127 had larger direct view optical viewfinders together with a curved film path to help br Rangefinder camera br Main article Rangefinder camera br As camera and lens technology developed and wide aperture lenses became more common range finder cameras were introduced to make focussing more precise The range finder had two separated viewfinder windows one of which was linked to the focusing mechanisms and moved right or left as the focussing ring was turned The two separate images were brought together on a ground glass viewing screen When vertical lines in the object being photographed met exactly in the combined image the object was in focus A normal composition viewfinder was also provided br')
About the Author
I am an expert from China Products, usually analyzes all kind of industries situation, such as self inflating mats , folding camping stool.
"Man With A Movie Camera" (1929)
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