A flash is a device used in photography producing a flash of artificial light at a color temperature of about 5500 K to help illuminate a scene. A major purpose of a flash is to illuminate a dark scene, other uses are capturing quickly moving objects or changing the quality of light. Flash refers either to the flash of light itself or to the flash unit discharging the light. Most current flash units are electronic, having evolved from single-use flashbulbs, modern cameras often activate flash units automatically. Flash units are built directly into a camera. Some cameras allow separate flash units to be mounted via an accessory mount bracket. In professional studio equipment, flashes may be large, standalone units, or studio strobes, studies of magnesium by Bunsen and Roscoe in 1859 showed that burning this metal produced a light with similar qualities to daylight. The potential application to photography inspired Edward Sonstadt to investigate methods of manufacturing magnesium so that it would burn reliably for this use and he applied for patents in 1862 and by 1864 had started the Manchester Magnesium Company with Edward Mellor.
It had the benefit of being a simpler and cheaper process than making round wire, mather was credited with the invention of a holder for the ribbon, which formed a lamp to burn it in. The packaging implies that the ribbon was not necessarily broken off before being ignited. An alternative to ribbon was flash powder, a mixture of powder and potassium chlorate, introduced by its German inventors Adolf Miethe. A measured amount was put into a pan or trough and ignited by hand, producing a brilliant flash of light, along with the smoke. This could be an activity, especially if the flash powder was damp. An electrically triggered flash lamp was invented by Joshua Lionel Cowen in 1899 and his patent describes a device for igniting photographers’ flash powder by using dry cell batteries to heat a wire fuse. Variations and alternatives were touted from time to time and a few found a measure of success in the marketplace, especially for amateur use. The use of powder in an open lamp was replaced by flashbulbs, magnesium filaments were contained in bulbs filled with oxygen gas.
Manufactured flashbulbs were first produced commercially in Germany in 1929, such a bulb could only be used once, and was too hot to handle immediately after use, but the confinement of what would otherwise have amounted to a small explosion was an important advance. A innovation was the coating of flashbulbs with a film to maintain bulb integrity in the event of the glass shattering during the flash
Digital zoom is a method of decreasing the apparent angle of view of a digital photographic or video image. It is accomplished electronically, with no adjustment of the cameras optics, in the former case, digital zoom tends to be superior to enlargement in post-processing, because the camera may apply its interpolation before detail is lost to compression. In the latter case, resizing in post-production yields results equal or superior to digital zoom, modest camera phones use only digital zoom and have no optical zoom at all. Usually cameras have an optical lens, but apply digital zoom automatically once its longest optical focal length has been reached. Professional cameras generally do not feature digital zoom, Digital zoom use the center area of the optical image to enlarge the image. By reducing the MP image size, using digital zoom can be done without image deterioration and some cameras has Undeteriorated image mode or at least has Image deterioration indicator. The table below give Undeteriorated zoom limit for some MP image size of a camera with Optical zoom 24x and Digital zoom 4x for its maximum capability, Note.
The table above has shown that from 3MP jumps directly too much too VGA and this camera has no option of 2MP and 1. 3MP, but other cameras have it. When using digital zoom for video, the camera can take up to 382. 6x magnification in VGA with Deteriorated image quality, but because video take multiframes per second, so between Deteriorated image quality and Undeteriorated image quality will be not much different. Nowadays cameras usually have iZoom with usually additional magnification 2x of its optical zoom, the iZoom use only center of the lens and not make any interpolation to original full resolution, so it save its good images quality in reduced resolution. The terms among camera manufacturers are “Smart Zoom”, “Safe Zoom”, there is camera with digital zoom 7. 2x and smartzoom with approximately 30x total zoom for 7MP from 16MP total resolution and 144x total zoom for VGA 640x480. Some photographers purposefully employ digital zoom for the low fidelity appearance of the images it produces.
This community thinks that poor quality photographs imply the carelessness of the photographer and thus, the notion that it is possible to achieve authenticity through pre-meditated carelessness inspires Lo-fi music. Image scaling Teleside converter - a secondary lens made for fixed lenses that increases the focal length, uses as a filter Zoom lens
A color space is a specific organization of colors. In combination with physical device profiling, it allows for reproducible representations of color, for example, Adobe RGB and sRGB are two different absolute color spaces, both based on the RGB color model. When defining a color space, the reference standard is the CIELAB or CIEXYZ color spaces. For example, although several specific color spaces are based on the RGB color model, colors can be created in printing with color spaces based on the CMYK color model, using the subtractive primary colors of pigment. The resulting 3-D space provides a position for every possible color that can be created by combining those three pigments. Colors can be created on computer monitors with color spaces based on the RGB color model, a three-dimensional representation would assign each of the three colors to the X, Y, and Z axes. Note that colors generated on given monitor will be limited by the medium, such as the phosphor or filters. Another way of creating colors on a monitor is with an HSL or HSV color space, based on hue, with such a space, the variables are assigned to cylindrical coordinates.
Many color spaces can be represented as three-dimensional values in this manner, but some have more, or fewer dimensions, Color space conversion is the translation of the representation of a color from one basis to another. The RGB color model is implemented in different ways, depending on the capabilities of the system used, by far the most common general-used incarnation as of 2006 is the 24-bit implementation, with 8 bits, or 256 discrete levels of color per channel. Any color space based on such a 24-bit RGB model is limited to a range of 256×256×256 ≈16.7 million colors. Some implementations use 16 bits per component for 48 bits total and this is especially important when working with wide-gamut color spaces, or when a large number of digital filtering algorithms are used consecutively. The same principle applies for any color space based on the color model. CIE1931 XYZ color space was one of the first attempts to produce a space based on measurements of human color perception. The CIERGB color space is a companion of CIE XYZ.
Additional derivatives of CIE XYZ include the CIELUV, CIEUVW, RGB uses additive color mixing, because it describes what kind of light needs to be emitted to produce a given color. RGB stores individual values for red and blue, RGBA is RGB with an additional channel, alpha, to indicate transparency. Common color spaces based on the RGB model include sRGB, Adobe RGB, ProPhoto RGB, scRGB, one starts with a white substrate, and uses ink to subtract color from white to create an image
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 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, 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 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
In photography, the metering mode refers to the way in which a camera determines the exposure. Cameras generally allow the user to select between spot, center-weighted average, or multi-zone metering modes, various metering modes are provided to allow the user to select the most appropriate one for use in a variety of lighting conditions. With spot metering, the camera will only measure a small area of the scene. This will by default be the centre of the scene. The user can select a different off-centre spot, or to recompose by moving the camera after metering. The first spot meter was built by Arthur James Dalladay, editor of The British Journal of Photography in about 1935, a few models support a Multi-Spot mode which allows multiple spot meter readings to be taken of a scene that are averaged. Some cameras, the OM-4 and T90 included, support metering of highlight, spot metering is very accurate and is not influenced by other areas in the frame. It is commonly used to very high contrast scenes.
The area around the back and hairline will become over-exposed, spot metering is a method upon which the Zone System depends. In many cases the camera will over or underexpose, when using the spot mode, modern cameras tend to find the correct exposure precisely. In complex light situations though, professional photographers tend to switch to manual mode, another example of spot metering usage would be when photographing the moon. Due to the dark nature of the scene, other metering methods tend to overexpose the moon. Spot metering will allow for more detail to be out in the moon while underexposing the rest of the scene. More commonly, spot metering is used in photography, where the brightly lit actors stand before a dark or even black curtain or scrim. Spot metering only considers the actors in this case, while ignoring the overall darkness of the scene, in this system, the meter concentrates between 60 to 80 percent of the sensitivity towards the central part of the viewfinder. The balance is feathered out towards the edges, some cameras will allow the user to adjust the weight/balance of the central portion to the peripheral one.
When moving the point off center the camera will proceed as above. Although promoted as a feature, center-weighted metering was originally a consequence of the meter cell reading from the screen of SLR cameras
Film speed is the measure of a photographic films sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system. A closely related ISO system is used to measure the sensitivity of digital imaging systems, highly sensitive films are correspondingly termed fast films. In both digital and film photography, the reduction of exposure corresponding to use of higher sensitivities generally leads to reduced image quality, in short, the higher the sensitivity, the grainier the image will be. Ultimately sensitivity is limited by the efficiency of the film or sensor. The speed of the emulsion was expressed in degrees Warnerke corresponding with the last number visible on the plate after development. Each number represented an increase of 1/3 in speed, typical speeds were between 10° and 25° Warnerke at the time. The concept, was built upon in 1900 by Henry Chapman Jones in the development of his plate tester. In their system, speed numbers were inversely proportional to the exposure required, for example, an emulsion rated at 250 H&D would require ten times the exposure of an emulsion rated at 2500 H&D.
The methods to determine the sensitivity were modified in 1925, the H&D system was officially accepted as a standard in the former Soviet Union from 1928 until September 1951, when it was superseded by GOST 2817-50. The Scheinergrade system was devised by the German astronomer Julius Scheiner in 1894 originally as a method of comparing the speeds of plates used for astronomical photography, Scheiners system rated the speed of a plate by the least exposure to produce a visible darkening upon development. ≈2 The system was extended to cover larger ranges and some of its practical shortcomings were addressed by the Austrian scientist Josef Maria Eder. Scheiners system was abandoned in Germany, when the standardized DIN system was introduced in 1934. In various forms, it continued to be in use in other countries for some time. The DIN system, officially DIN standard 4512 by Deutsches Institut für Normung, was published in January 1934, International Congress of Photography held in Dresden from August 3 to 8,1931.
The DIN system was inspired by Scheiners system, but the sensitivities were represented as the base 10 logarithm of the sensitivity multiplied by 10, similar to decibels. Thus an increase of 20° represented an increase in sensitivity. ≈3 /10 As in the Scheiner system, speeds were expressed in degrees, originally the sensitivity was written as a fraction with tenths, where the resultant value 1.8 represented the relative base 10 logarithm of the speed. Tenths were abandoned with DIN4512, 1957-11, and the example above would be written as 18° DIN, the degree symbol was finally dropped with DIN4512, 1961-10
It is not used in JPEG2000, PNG, or GIF. This standard consists of the Exif image file specification and the Exif audio file specification, the Japan Electronic Industries Development Association produced the initial definition of Exif. Version 2.1 of the specification is dated 12 June 1998, JEITA established Exif version 2.2, dated 20 February 2002 and released in April 2002. Version 2.21 is dated 11 July 2003, but was released in September 2003 following the release of DCF2.0, the latest, version 2.3, released on 26 April 2010 and revised in May 2013, was jointly formulated by JEITA and CIPA. Exif is supported by almost all camera manufacturers, the metadata tags defined in the Exif standard cover a broad spectrum and time information. Digital cameras will record the current date and time and save this in the metadata, a thumbnail for previewing the picture on the cameras LCD screen, in file managers, or in photo manipulation software. The Exif tag structure is borrowed from TIFF files, on several image specific properties, there is a large overlap between the tags defined in the TIFF, Exif, TIFF/EP, and DCF standards.
For descriptive metadata, there is an overlap between Exif, IPTC Information Interchange Model and XMP info, which can be embedded in a JPEG file, the Metadata Working Group has guidelines on mapping tags between these standards. When Exif is employed for JPEG files, the Exif data are stored in one of JPEGs defined utility Application Segments, the APP1, when Exif is employed in TIFF files, the TIFF Private Tag 0x8769 defines a sub-Image File Directory that holds the Exif specified TIFF Tags. Formats specified in Exif standard are defined as structures that are based on Exif-JPEG. When these formats are used as Exif/DCF files together with the DCF specification, their scope shall cover devices, recording media, the Exif format has standard tags for location information. As of 2014 many cameras and most mobile phones have a built-in GPS receiver that stores the information in the Exif header when a picture is taken. Some other cameras have a separate GPS receiver that fits into the connector or hot shoe.
The process of adding information to a photograph is known as geotagging. Photo-sharing communities like Panoramio, locr or Flickr equally allow their users to upload geocoded pictures or to add geolocation information online, Exif data are embedded within the image file itself. While many recent image manipulation programs recognize and preserve Exif data when writing to a modified image, many image gallery programs recognise Exif data and optionally display it alongside the images. The Exif format has a number of drawbacks, mostly relating to its use of file structures. For this reason most image editors damage or remove the Exif metadata to some extent upon saving, the standard defines a MakerNote tag, which allows camera manufacturers to place any custom format metadata in the file
St. Matthew's German Evangelical Lutheran Church
The German Evangelical Lutheran Church of Charleston, South Carolina, was incorporated on December 3,1840. The church was founded by Johann Andreas Wagener and 49 other German-speaking citizens wishing to worship in their language in the port city of Charleston. Wageners first intent was to form a German language, cosmopolitan congregation for all faiths, Reformed, when the ecumenical plan failed, it was decided to organize the congregation as an Evangelical Lutheran Church. Wagener was elected the congregations first president and he establish the town of Walhalla, South Carolina in 1849 as a colony for German immigrants. Later he became a Brigadier General in the Confederate States Army, in 1866, he represented the Charleston district in the South Carolina House of Representatives, and in 1871 Wagener was elected mayor of Charleston. The congregations first purchase was a cemetery for the burial of German-speaking citizens during a fever outbreak in 1841. Known as Hampstedt or Gods Acre Cemetery, the ground on Reid Street held 1,048 graves by the mid-1850s.
Johns Lutheran Church on Clifford St. Interestingly, the Presbyterian Lecture Room was purchased by the Roman Catholic Diocese of Charleston in 1861 to form St. Pauls German Catholic Church. The Lutheran congregations first church building was a classical Greek Revival structure on the northwest corner of Hasell, the architect was Edward Brickell White, and it was dedicated on June 22,1842. The cost for the land and construction by John Dawson was $11,000, in 1856 the church purchased Bethany Cemetery because the first cemetery was full. There were several yellow fever outbreaks during the early years of the congregation. According to church records, there were 147 deaths in 1854,308 in 1858 and 130 in 1865 of which 84 were children, during the worst outbreaks, Pastor Ludwig Louis Müller officiated at three funerals every day. During the American Civil War, only the windows and some furnishings were damaged during the Siege of Charleston. By 1860, Germans represented 5% of the Charleston population, the congregation had outgrown the original sanctuary by 1868 when 40 applications for pews could not be filled.
In 1878 the sanctuary was sold to a group of 53 Lutherans who formed the German Evangelical Lutheran St. Johannes Church, devereux designed the Renaissance Revival U. S. The new sanctuary was dedicated in 1872 with elaborate ceremonies and 3000 persons attending, in 1883, the church began to hold services in German and English. In 1901, a clock and set of ten bells from the Meneely Bell Foundry were installed in the steeple at a cost of $7000, a Sunday school building was added in 1909. As the nation entered the Great War in 1917,83 members of the joined the military
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
In photography and image processing, color balance is the global adjustment of the intensities of the colors. An important goal of this adjustment is to specific colors – particularly neutral colors – correctly. Hence, the method is sometimes called gray balance, neutral balance. Color balance changes the mixture of colors in an image and is used for color correction. Generalized versions of color balance are used to correct colors other than neutrals or to change them for effect. Image data acquired by sensors – either film or electronic image sensors – must be transformed from the values to new values that are appropriate for color reproduction or display. In film photography, color balance is achieved by using color correction filters over the lights or on the camera lens. It is particularly important that neutral colors in a scene appear neutral in the reproduction, most digital cameras have means to select color correction based on the type of scene lighting, using either manual lighting selection, automatic white balance, or custom white balance.
The algorithms for these processes perform generalized chromatic adaptation, many methods exist for color balancing. Setting a button on a camera is a way for the user to indicate to the processor the nature of the scene lighting, another option on some cameras is a button which one may press when the camera is pointed at a gray card or other neutral colored object. This captures an image of the ambient light, which enables a digital camera to set the color balance for that light. There is a literature on how one might estimate the ambient lighting from the camera data. A variety of algorithms have been proposed, and the quality of these has been debated, a few examples and examination of the references therein will lead the reader to many others. Examples are Retinex, a neural network or a Bayesian method. Color balancing an image not only the neutrals, but other colors as well. An image that is not color balanced is said to have a color cast, Color balancing may be thought in terms of removing this color cast.
Color balance is related to color constancy. Algorithms and techniques used to color constancy are frequently used for color balancing
Factors considered may include unusual lighting distribution, variations within a camera system, non-standard processing, or intended underexposure or overexposure. Cinematographers may apply exposure compensation for changes in angle or film speed. Most DSLR cameras have a display whereby the photographer can set the camera to either over or under expose the subject by up to three f-stops in 1/3rd stop intervals. Each number on the scale represents one f-stop, decreasing the exposure by one f-stop will halve the amount of light reaching the sensor, the dots in between the numbers represent 1/3rd of an f-stop. In photography, some cameras include exposure compensation as a feature to allow the user to adjust the automatically calculated exposure, camera exposure compensation is commonly stated in terms of EV units,1 EV is equal to one exposure step, corresponding to a doubling of exposure. Exposure can be adjusted by changing either the lens f-number or the exposure time, if the mode is aperture priority, exposure compensation changes the exposure time, if the mode is shutter priority, the f-number is changed.
If a flash is being used, some cameras will adjust it as well, the earliest reflected-light exposure meters were wide-angle, averaging types, measuring the average scene luminance. When measuring a scene with atypical distribution of light and dark elements, or an element that is lighter or darker than a middle tone. For example, a scene with predominantly light tones often will be underexposed and that both scenes require the same exposure, regardless of the meter indication, becomes obvious from a scene that includes both a white horse and a black horse. A photographer usually can recognize the difference between a horse and a black horse, a meter usually cannot. When metering a white horse, a photographer can apply exposure compensation so that the horse is rendered as white. Many modern cameras incorporate metering systems that measure scene contrast as well as average luminance, in scenes with very unusual lighting, these metering systems sometimes cannot match the judgment of a skilled photographer, so exposure compensation still may be needed.
An early application of compensation was the Zone System developed by Ansel Adams. Developed for black-and-white film, the Zone System divided luminance into 11 zones, with Zone 0 representing pure black, the meter indication would place whatever was metered on Zone V, a medium gray. The meter indication, remains Zone V, the Zone System is a very specialized form of exposure compensation, and is used most effectively when metering individual scene elements, such as a sunlit rock or the bark of a tree in shade. Many cameras incorporate narrow-angle spot meters to facilitate such measurements, because of the limited tonal range, an exposure compensation range of ±2 EV is often sufficient for using the Zone System with color film and digital sensors. Exposure value Exposure index Light meter Zone System Exposure bracketing Auto Exposure Bracketing
Canon PowerShot G
The Canon PowerShot G is a series of digital cameras released by Canon. The G series cameras are Canons flagship compact models aimed at photography enthusiasts desiring more flexibility than a point-and-shoot without the bulk of a digital single-lens reflex camera, the range includes a hot shoe for an external flashgun, including Canons EX range. Three models in the series have larger sensors than most other point-and-shoot cameras, common features across the early G series were, A fast lens. A flip out and twist LCD, along with a smaller status LCD on the top of the camera, manual selection of aperture and shutter priority. Availability of optional wide and teleconverter lenses, canon’s proprietary EOS shooting modes, allowing the photographer to select different exposure settings for different environments. In-built neutral density filter from the G3 onwards, the G7 marked a major change in the G series. Previous G series models had featured a fast lens, Raw image format capture, and these were all considered hallmark features of the G series, but were removed or altered for the G7.
Some of the changes included, Introduction of a lens with a minimum F number of 2.8. Although slower, this lens introduced improvements such as optical image stabilisation, a higher range. The lens would retract completely into the camera, change to a fixed LCD rather than a tilt-and-swivel model. The fixed LCD was larger and increased the number of pixels by 75%, the tilt-and swivel LCD was restored with the G11, but removed again with the G15. Removal of RAW image format on G7, but returned for the G9–G15, change from CompactFlash to SDHC card storage. Canon G12 records videos up to 720p HD quality, G15 1080p HD, G15 and G1 X do allow to use zoom and autofocus during video recording. Many of the changes made allowed the G7 to be slimmer than previous G series cameras. Canons removal of RAW shooting support was heavily criticized, RAW support can be enabled on the G7 using a free firmware add-on. The G9 was released in 2007, among its features were restored RAW support, a larger LCD screen, and a 1/1. 7″ sensor rather than the 1/1. 8″ sensor on previous models.
The G11, released in 2009, reintroduced the flip out and it features a lower resolution sensor than that of its predecessor, the G10, because the new CCD favoured low light performance over resolution. The G1 X was introduced in February 2012 and is a significant step out of the traditional G-line because of its much larger sensor, and it is the first model featuring a CMOS sensor