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1. San Francisco Municipal Railway fleet – Roughly 800 buses,200 streetcars and 40 cable cars see active duty. Munis cable cars constitute the oldest and largest such remaining in service in the world and is the only one still running with manually operated cars in street traffic. Its fleet of trolleybuses is the largest in the United States. Muni is in the process of replacing its motor coach fleet - the first of which was procured in 1915 - with diesel-electric hybrid buses, a summary of the current and historic vehicles follows. §5454,6238,6244,6259,6291,8173,6238,6244,6291, and 8173 written off due to a fire, and 5454,6259, and 8319 written off due to an accident. ^8448 Wi-Fi equipped from 2008 to 2009, the Connected bus, ♦8101-8235 and 8301-71s turn signal is different when rehabilitated in 2013. Muni also tested a 40-foot double-decker bus from Alexander Dennis Limited but the bus is now retired. As the Neoplan buses are assigned to the reserve fleet. Reserve fleet buses are only in service as needed, the following are a list of buses that are currently assigned to the training fleet. These buses are sometimes revenue service as reserve fleet, and are used to train prospective operators, the following shows the buses previously operated by the SFMTA. Some of these coaches have been preserved in the fleet, donated to trolley museums. There are 11 divisions for the Muni buses, ETI 14TrSF Skodas #5401-5489 and NFI XT60 Vossloh Kiepe #7201-7260 are from the Potrero Division, while #5490-5640 are from the Presidio Division, the latter holds only 40-ft ETI Skoda trolleybuses. The Kirkland Division uses only Neoplan AN440 diesel buses, the 30 and 40-ft Orion VII diesel-electric hybrid buses, and New Flyer XDE40s all rest in the Woods Division. Some Neoplan AN440s also lie in the Woods division as the fleet and are used only as needed. The division where the Neoplan AN440s that are rehabbed in 2013 lies in are the Kirkland Division, the test buses that retired that is moved. Munis active diesel fleet contains coaches ranging from thirty to sixty feet in length, for the last complete fleet replacement cycle Muni bought from three manufacturers, NABI, Neoplan and Orion, all of whom no longer sell buses in the U. S. Muni has since purchased 40 ft. and 60 ft. buses from New Flyer with options to replace the remainder of the fleet in those sizes. In 1984, Muni received its first 60-ft articulated buses, which were used on high-ridership routes because the buses carried more people than the standard length bus, in December 2007, Muni acquired a double-decker diesel bus for testing purposes
2. Canon Inc. – It is headquartered in Ōta, Tokyo, Japan. Canon has a listing on the Tokyo Stock Exchange and is a constituent of the TOPIX index. It has a listing on the New York Stock Exchange. At the beginning of 2015, Canon was the tenth largest public company in Japan when measured by market capitalization, the company was originally named Seikikōgaku kenkyūsho. In 1934 it produced the Kwanon, a prototype for Japan’s first-ever 35 mm camera with a plane based shutter. In 1947 the company name was changed to Canon Camera Co. Inc. shortened to Canon Inc. in 1969, the name Canon comes from Buddhist bodhisattva Guan Yin, previously transliterated as Kuanyin, Kwannon, or Kwanon in English. The origins of Canon date back to the founding of Precision Optical Instruments Laboratory in Japan in 1937 by Takeshi Mitarai, Goro Yoshida, Saburo Uchida and Takeo Maeda. During its early years the company did not have any facilities to produce its own optical glass, between 1933 and 1936 ‘The Kwanon’, a copy of the Leica design, Japan’s first 35 mm focal plane-shutter camera, was developed in prototype form. In 1940 Canon developed Japans first indirect X-ray camera, Canon introduced a field zoom lens for television broadcasting in 1958 and in 1959 introduced the Reflex Zoom 8, the world’s first movie camera with a zoom lens, and the Canonflex. In 1961 Canon introduced the Rangefinder camera, Canon 7, in 1965 Canon introduced the Canon Pellix, a single lens reflex camera with a semi-transparent stationary mirror which enabled the taking of pictures through the mirror. In 1971 Canon introduced the F-1, a high-end SLR camera, in 1976 Canon launched the AE-1, the world’s first camera with an embedded micro-computer. In 1982 Wildlife as Canon Sees It print ads first appeared in National Geographic magazine, Canon introduced the world’s first Inkjet printer using bubble jet technology in 1985. Canon introduced Canon Electro-Optical System in 1987, named after the goddess of the dawn, EOS650 autofocus SLR camera is introduced. Also in 1987 the Canon Foundation was established, in 1988 Canon introduced Kyosei philosophy. The EOS1 Flagship Professional SLR line was launched in 1989, in the same year the EOS RT, the worlds first AF SLR with a fixed, semi-transparent pellicle mirror, was unveiled. In 1992 Canon launched the EOS5, the camera with eye-controlled AF. In 1995 Canon introduced the first commercially available SLR lens with image stabilization. EOS-1N RS, the worlds fastest AF SLR camera with a shooting speed of 10 frame/s at the time
3. 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 also 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 also 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 also 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
4. Shutter speed – 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
5. F-number – The f-number of an optical system such as a camera lens is the ratio of the systems focal length to the diameter of the entrance pupil. It is a number that is a quantitative measure of lens speed. It is also known as the ratio, f-ratio, f-stop. The f-number is commonly indicated using a hooked f with the format f/N, the f-number N or f# is given by, N = f D where f is the focal length, and D is the diameter of the entrance pupil. It is customary to write f-numbers preceded by f/, which forms a mathematical expression of the pupil diameter in terms of f and N. Ignoring differences in light transmission efficiency, a lens with a greater f-number projects darker images, the brightness of the projected image relative to the brightness of the scene in the lenss field of view decreases with the square of the f-number. Doubling the f-number decreases the brightness by a factor of four. To maintain the same photographic exposure when doubling the f-number, the time would need to be four times as long. Most lenses have a diaphragm, which changes the size of the aperture stop. The entrance pupil diameter is not necessarily equal to the aperture stop diameter, a 100 mm focal length f/4 lens has an entrance pupil diameter of 25 mm. A200 mm focal length f/4 lens has a pupil diameter of 50 mm. The 200 mm lenss entrance pupil has four times the area of the 100 mm lenss entrance pupil, a T-stop is an f-number adjusted to account for light transmission efficiency. The word stop is sometimes confusing due to its multiple meanings, a stop can be a physical object, an opaque part of an optical system that blocks certain rays. In photography, stops are also a used to quantify ratios of light or exposure. The one-stop unit is known as the EV unit. On a camera, the setting is traditionally adjusted in discrete steps. Each stop is marked with its corresponding f-number, and represents a halving of the light intensity from the previous stop. This corresponds to a decrease of the pupil and aperture diameters by a factor of 1/2 or about 0.7071, each element in the sequence is one stop lower than the element to its left, and one stop higher than the element to its right
6. Film speed – 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 then 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, however, 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 later 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 later 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
7. Focal length – 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
8. Picasa – Picasa is a discontinued image organizer and image viewer for organizing and editing digital photos, plus an integrated photo-sharing website, originally created by a company named Lifescape in 2002. In July 2004, Google acquired Picasa from Lifescape and began offering it as freeware, Picasa is a blend of the name of Spanish painter Pablo Picasso, the phrase mi casa and pic for pictures. Native applications for Windows XP, Windows Vista, Windows 7, for Linux, Google bundled Wine with the Windows version to create an installation package. For Mac OS X10.4 and later, Google also released an iPhoto plugin and a standalone program for uploading photos. On February 12,2016, Google announced it was discontinuing support for Picasa Desktop and Web Albums, effective March 15,2016, Picasa Web Albums, a companion service, was closed on May 1,2016. As of January 2015, the latest version of Picasa is 3.9, which supports Windows XP, Windows Vista, and Windows 7, version 3.9 also removed integration with Picasa Web Albums for users of Google+. Since June 2006, Linux versions have become available as downloads for most distributions of the Linux operating system. It is not a native Linux program but an adapted Windows version that uses the Wine libraries, Google has announced that there will be no Linux version for 3.5. Currently, Google has only officially offered Picasa 3.0 Beta for Linux, on April 20,2012 Google announced that they were deprecating Picasa for Linux and will no longer maintain it on that operating system. To use latest version of Picasa on Linux, Linux users can use Wine, Linux users can use other programs to upload to Picasa Web Albums, including Shotwell and Digikam. On January 5,2009, Google released a version of Picasa for Mac. Also, a plugin is available for iPhoto to upload to the Picasa Web Albums hosting service, there is also a standalone Picasa Web Albums uploading tools for OS X10.4 or later. The Picasa for Mac is a Google Labs release, for organizing photos, Picasa has file importing and tracking features, as well as tags, facial recognition, and collections for further sorting. It also offers several basic photo editing functions, including color enhancement, red eye reduction, other features include slide shows, printing, and image timelines. Images can also be prepared for use, such as for e-mailing or printing, by reducing file size. There is also integration with online photo printing services, other simple editing features include adding text to the image. Picasa supports Googles WebP image format as well as the JPG format, a user can view and edit RAW files and save the finished edit without any changes to the original RAW file. Picasa uses picasa. ini files to track of keywords for each image
9. Exif – 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, Date 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 also 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 also 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
10. Exposure compensation – Factors considered may include unusual lighting distribution, variations within a camera system, filters, non-standard processing, or intended underexposure or overexposure. Cinematographers may also 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, however, 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, however, 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
11. Metering mode – 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, also 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 then 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 then 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
12. Flash (photography) – 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 also had the benefit of being a simpler and cheaper process than making round wire, mather was also credited with the invention of a holder for the ribbon, which formed a lamp to burn it in. The packaging also 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 later innovation was the coating of flashbulbs with a film to maintain bulb integrity in the event of the glass shattering during the flash