|
|
| (One intermediate revision by one other user not shown) |
| Line 1: |
Line 1: |
| [[File:Shutter speed waterfall.gif|frame|Shutter speed can have a dramatic impact on the appearance of moving objects. Changes in background blurring are apparent from the need to adjust the [[aperture]] size to achieve proper exposure.]] <!-- Don't thumb this, mediawiki animation scaling is broken and will make it ugly and bigger -->
| | <br><br>It is very common to have a dental emergency -- a fractured tooth, an abscess, or severe pain when chewing. Over-the-counter pain medication is just masking the problem. Seeing an emergency dentist is critical to getting the source of the problem diagnosed and corrected as soon as possible.<br><br>Here are some common dental emergencies:<br>Toothache: The most common dental emergency. This generally means a badly decayed tooth. As the pain affects the tooth's nerve, treatment involves gently removing any debris lodged in the cavity being careful not to poke deep as this will cause severe pain if the nerve is touched. Next rinse vigorously with warm water. Then soak a small piece of cotton in oil of cloves and insert it in the cavity. This will give temporary relief until a dentist can be reached.<br><br>At times the pain may have a more obscure location such as decay under an old filling. As this can be only corrected by a dentist there are two things you can do to help the pain. Administer a pain pill (aspirin or some other analgesic) internally or dissolve a tablet in a half glass (4 oz) of warm water holding it in the mouth for several minutes before spitting it out. DO NOT PLACE A WHOLE TABLET OR ANY PART OF IT IN THE TOOTH OR AGAINST THE SOFT GUM TISSUE AS IT WILL RESULT IN A NASTY BURN.<br><br>Swollen Jaw: This may be caused by several conditions the most probable being an abscessed tooth. In any case the treatment should be to reduce pain and swelling. An ice pack held on the outside of the jaw, (ten minutes on and ten minutes off) will take care of both. If this does not control the pain, an analgesic tablet can be given every four hours.<br><br>Other Oral Injuries: Broken teeth, cut lips, bitten tongue or lips if severe means a trip to a dentist as soon as possible. In the mean time rinse the mouth with warm water and place cold compression the face opposite the injury. If there is a lot of bleeding, apply direct pressure to the bleeding area. If bleeding does not stop get patient to the emergency room of a hospital as stitches may be necessary.<br><br>Prolonged Bleeding Following Extraction: Place a gauze pad or better still a moistened tea bag over the socket and have the patient bite down gently on it for 30 to 45 minutes. The tannic acid in the tea seeps into the tissues and often helps stop the bleeding. If bleeding continues after two hours, call the dentist or take patient to the emergency room of the nearest hospital.<br><br>Broken Jaw: If you suspect the patient's jaw is broken, bring the upper and lower teeth together. Put a necktie, handkerchief or towel under the chin, tying it over the head to immobilize the jaw until you can get the patient to a dentist or the emergency room of a hospital.<br><br>Painful Erupting Tooth: In young children teething pain can come from a loose baby tooth or from an erupting permanent tooth. Some relief can be given by crushing a little ice and wrapping it in gauze or a clean piece of cloth and putting it directly on the tooth or gum tissue where it hurts. The numbing effect of the cold, along with an appropriate dose of aspirin, usually provides temporary relief.<br><br>In young adults, an erupting 3rd molar (Wisdom tooth), especially if it is impacted, can cause the jaw to swell and be quite painful. Often the gum around the tooth will show signs of infection. Temporary relief can be had by giving aspirin or some other painkiller and by dissolving an aspirin in half a glass of warm water and holding this solution in the mouth over the sore gum. AGAIN DO NOT PLACE A TABLET DIRECTLY OVER THE GUM OR CHEEK OR USE THE ASPIRIN SOLUTION ANY STRONGER THAN RECOMMENDED TO PREVENT BURNING THE TISSUE. The swelling of the jaw can be reduced by using an ice pack on the outside of the face at intervals of ten minutes on and ten minutes off.<br><br>If you have any concerns regarding where and how you can make use of [http://www.youtube.com/watch?v=90z1mmiwNS8 dentist DC], you could contact us at the webpage. |
| [[File:Nikkormat shutterspeeddial top.jpg|thumb|upright|The shutter speed dial of a [[Nikkormat|Nikkormat EL]]]]
| |
| [[File:Truck with motion blur.jpg|thumb|Slow shutter speed combined with panning the camera can achieve a motion blur for moving objects.]]
| |
| | |
| In [[photography]], '''shutter speed''' or '''exposure time''' is the length of time a [[camera]]'s [[shutter (photography)|shutter]] is open when taking a photograph.<ref name=ray>
| |
| {{cite book | title = Manual of Photography: A Textbook of Photographic and Digital Imaging | chapter = Camera Features | pages = 131–132 | author = Sidney F. Ray | editor = Ralph Eric Jacobson et al. | url = http://books.google.com/books?id=HHX4xB94vcMC&pg=PA132&ots=7Gq_Az_-zl&dq=standard-series+%22shutter+speed%22&sig=bQ5bvKIS-y1_Q4km6Pm-yCZDcGo | publisher = Focal Press | edition = Ninth ed. | isbn = 0-240-51574-9 | year = 2000 }}
| |
| </ref>
| |
| The amount of light that reaches the [[Photographic film|film]] or [[image sensor]] is proportional to the exposure time.
| |
| | |
| ==Introduction==
| |
| The camera's shutter speed, the lens's brightness ([[f-number]]), and the scene's [[luminance]] together determine the amount of light that reaches the film or sensor (the [[exposure (photography)|exposure]]). [[Exposure value]] (EV) is a single quantity that accounts for the shutter speed and the f-number.
| |
| | |
| Multiple combinations of shutter speed and f-number can give the same exposure value. Doubling the exposure time doubles the amount of light (subtracts 1 EV). Making the f-number one stop brighter (reducing the f-number by a factor of <math>\scriptstyle \sqrt{2}</math>) also doubles the amount of light. A shutter speed of 1/50 s with an {{f/}}4.0 lens gives the same exposure value as a 1/100 s shutter with an {{f/}}2.8 lens, and also the same exposure value as a 1/200 s shutter with an {{f/}}2.0 lens.
| |
| | |
| In addition to its effect on exposure, the shutter speed changes the way movement appears in photographs. Very short shutter speeds can be used to freeze fast-moving subjects, for example at sporting events. Very long shutter speeds are used to intentionally blur a moving subject for artistic effect.<ref>{{cite book | title = The Complete Guide to Night and Low-Light Photography | author = Lee Frost | publisher = Amphoto Books | year = 2000 | isbn = 0-8174-5041-6 | url = http://books.google.com/books?id=IugNeG0vIMcC&pg=RA1-PA142&ots=aA3puq4Dv2&dq=intentionally+blur+moving+%22shutter+speed%22&sig=ZujwjyJB5n7dQ-3-km1vyLoSEEc#PRA1-PA141,M1 }}</ref> Short exposure times are sometimes called "fast", and long exposure times "slow".
| |
| | |
| Adjustment to the aperture controls the [[depth of field]], the distance range over which objects are acceptably sharp; such adjustments need to be compensated by changes in the shutter speed.
| |
| | |
| In early days of photography, available shutter speeds were not standardized, though a typical sequence might have been 1/10 s, 1/25 s, 1/50 s, 1/100 s, 1/200 s and 1/500 s. Following the adoption of a standardized way of representing [[aperture]] so that each major step exactly doubled or halved the amount of light entering the camera ({{f/}}2.8, {{f/}}4, {{f/}}5.6, {{f/}}8, {{f/}}11, {{f/}}16, etc.), a standardized 2:1 scale was adopted for shutter speed so that opening one aperture stop and reducing the shutter speed by one step resulted in the identical exposure. The agreed standards for shutter speeds are:<ref name=kahn>{{cite book | title = Essential Skills for Nature Photography | author = Cub Kahn | url = http://books.google.com/books?id=EZhNY--TZjIC&pg=PT21&dq=%22standard+series%22+%22shutter+speed%22+1-1000&ei=h0MHSejTFI_gswOh3eDzDQ | isbn = 1-58428-009-3 | year = 1999 | publisher = Amherst Media}}</ref>
| |
| {{columns-list|4|
| |
| *1/1000 s
| |
| *1/500 s
| |
| *1/250 s
| |
| *1/125 s
| |
| *1/60 s
| |
| *1/30 s
| |
| *1/15 s
| |
| *1/8 s
| |
| *1/4 s
| |
| *1/2 s
| |
| *1 s
| |
| }}
| |
| | |
| [[Image:Phatman - Lightning on the Columbia River (by-sa).jpg|thumb|left|upright|An extended exposure can also allow photographers to catch brief flashes of light, as seen here. Exposure time 15 seconds.]]
| |
| | |
| With this scale, each increment roughly doubles the amount of light (longer time) or halves it (shorter time).
| |
| | |
| Camera shutters often include one or two other settings for making very long exposures:
| |
| * '''B''' (for ''[[bulb (photography)|bulb]]'') keeps the shutter open as long as the shutter release is held.
| |
| * '''T''' (for ''time'') keeps the shutter 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 slowest possible shutter speed for a handheld camera. The rough guide used by most [[135 film|35 mm]] photographers is that the slowest shutter speed that can be used easily without much blur due to camera shake is the shutter speed numerically closest to the lens focal length. For example, for handheld use of a 35 mm camera with a 50 mm [[normal lens]], the closest shutter speed is 1/60 s. This rule can be augmented with knowledge of the intended application for the photograph, an image intended for significant enlargement and closeup viewing would require faster shutter speeds to avoid obvious blur. Through practice and special techniques such as bracing the camera, arms, or body to minimize camera movement longer shutter speeds can be used without blur. If a shutter speed is too slow for hand holding, a camera support, usually a [[Tripod (photography)|tripod]], must be used. [[Image stabilization]] can often permit the use of shutter speeds 3–4 stops slower (exposures 8–16 times longer).
| |
| | |
| Shutter priority refers to a shooting mode used in semi-automatic cameras. It allows the photographer to choose a shutter speed setting and allow the camera to decide the correct aperture. This is sometimes referred to as [[shutter priority|Shutter Speed Priority Auto Exposure]], or TV (time value) mode.
| |
| | |
| ==Creative utility in photography==
| |
| {{main|Motion blur}}
| |
| | |
| {{multiple image
| |
| | align = right
| |
| | direction = horizontal
| |
| | image1 = E17 - korte sluitertijd.JPG
| |
| | alt1 =
| |
| | caption1 =
| |
| | image2 = E17 - lange sluitertijd.JPG
| |
| | alt2 =
| |
| | caption2 =
| |
| | footer = The photograph to the right was taken with a slower shutter speed than that to the left, creating a more pronounced motion blur effect and longer streaks of light from vehicle headlights.
| |
| }}
| |
| [[File:Sparklers with a slow shutter speed.JPG|thumb|Sparklers moved in a circular motion with an exposure time of 4 seconds. This is an example of [[Light painting]]]]
| |
| | |
| Shutter speed is one of several methods used to control the amount of light recorded by the camera's [[Image sensor|digital sensor]] or film. It is also used to manipulate the visual effects of the final image beyond its luminosity.
| |
| [[Image:Shutter speed pool.jpg|thumb|Images taken with a lower shutter speed invoke a visual sense of movement. Exposure time 3 seconds.]]
| |
| Slower shutter speeds are often selected to suggest movement in a still photograph of a moving subject.
| |
| | |
| Excessively fast shutter speeds can cause a moving subject to appear unnaturally frozen. For instance, a running person may be caught with both feet in the air with all indication of movement lost in the frozen moment.
| |
| | |
| When a slower shutter speed is selected, a longer time passes from the moment the shutter opens till the moment it closes. More time is available for movement in the subject to be recorded by the camera.
| |
| | |
| A slightly slower shutter speed will allow the photographer to introduce an element of blur, either in the subject, where, in our example, the feet, which are the fastest moving element in the frame, might be blurred while the rest remains sharp; or if the camera is [[panning (camera)|panned]] to follow a moving subject, the background is blurred while the subject remains sharp.
| |
| | |
| The exact point at which the background or subject will start to blur depends on the rate at which the object is moving, the angle that the object is moving in relation to the camera, the distance it is from the camera and the focal length of the lens in relation to the size of the digital sensor or film.
| |
| | |
| When slower shutter speeds, in excess of about half a second, are used on running water, the photo will have a ghostly white appearance reminiscent of [[fog]]. This effect can be used in [[landscape photography]].
| |
| | |
| [[Zoom burst]] is a technique which entails the variation of the focal length of a zoom lens during a longer exposure. In the moment that the shutter is opened, the lens is zoomed in, changing the focal length during the exposure. The center of the image remains sharp, while the details away from the center form a radial blur, which causes a strong visual effect, forcing the eye into the center of the image.<ref>{{cite web | work = Illustrated Photography | title = About Shutter Speed | url=http://www.illustratedphotography.com/basic-photography/understanding-shutter-speed}}</ref>
| |
| | |
| The following list provides an overview of common photographic uses for standard shutter speeds.
| |
| * ''1/16000 s'': The fastest speed available in [[APS-H]] or [[APS-C]] format [[DSLR]] cameras (as of 2012). ([[Canon (company)|Canon]] [[Canon EOS 1D|EOS 1D]], [[Nikon]] [[Nikon D1|D1]], Nikon 1 J2, [[Nikon D1X|D1X]], and [[Nikon D1H|D1H]])
| |
| * ''1/12000 s'': The fastest speed available in any [[35 mm]] film [[Single-lens reflex camera|SLR]] camera. ([[Minolta]] [[Minolta 9xi|Maxxum 9xi]], {{ill|de|Minolta Maxxum 9{{!}}Maxxum 9|Minolta Dynax 9}}''
| |
| * ''1/8000 s'': The fastest speed available in production [[Single-lens reflex camera|SLR]] cameras (as of 2013), also the fastest speed available in any [[Full-frame digital SLR|full-frame DSLR]] or [[Sony SLT camera|SLT]] camera (as of 2013). Used to take sharp photographs of very fast subjects, such as birds or planes, under good lighting conditions, with an [[ISO film speed|ISO speed]] of 1,000 or more and a large-aperture lens.<ref>Doeffinger, 5</ref>
| |
| * ''1/4000 s'': The fastest speed available in [[consumer]] SLR cameras (as of 2009); also the fastest speed available in any [[leaf shutter]] camera (such as the [[Sony Cyber-shot DSC-RX1]]) (as of 2013). Used to take sharp photographs of fast subjects, such as athletes or vehicles, under good lighting conditions and with an ISO setting of up to 800.<ref>Doeffinger, 6</ref>
| |
| * ''1/2000 s and 1/1000 s'': Used to take sharp photographs of moderately fast subjects under normal lighting conditions.<ref>Doeffinger, 7–12</ref>
| |
| * ''1/500 s and 1/250 s'': Used to take sharp photographs of people in motion in everyday situations. 1/250 s is the fastest speed useful for [[Panning (camera)|panning]]; it also allows for a smaller aperture (up to f/11) in motion shots, and hence for a greater depth of field.<ref>Doeffinger, 12–17</ref>
| |
| * ''1/125 s'': This speed, and slower ones, are no longer useful for freezing motion. 1/125 s is used to obtain greater depth of field and overall sharpness in [[landscape photography]], and is also often used for panning shots.
| |
| * ''1/60 s'': Used for panning shots, for images taken under dim lighting conditions, and for available light portraits.<ref>Doeffinger, 20–22</ref>
| |
| * ''1/30 s'': Used for panning subjects moving slower than {{convert|30|mph}} and for available-light photography. Images taken at this and slower speeds normally require a [[tripod]] or an [[Image stabilization|image stabilized]] lens/camera to be sharp.<ref>Doeffinger, 24</ref>
| |
| * ''1/15 s and 1/8 s'': This and slower speeds are useful for photographs other than panning shots where motion blur is employed for deliberate effect, or for taking sharp photographs of immobile subjects under bad lighting conditions with a tripod-supported camera.<ref>Doeffinger, 26–30</ref>
| |
| * ''1/4 s, 1/2 s and 1 s'': Also mainly used for motion blur effects and/or low-light photography, but only practical with a tripod-supported camera.<ref>Doeffinger, 32–40</ref>
| |
| * ''[[Bulb (photography)|B (bulb)]]'' (1 minute to several hours): Used with a mechanically fixed camera in [[astrophotography]] and for certain special effects.<ref>Doeffinger, 41 et seq.</ref>
| |
| <gallery widths="200px" heights="200px">
| |
| File:The NTT Spinning like a Top.jpg|30-second exposure of the rotating [[New Technology Telescope]]
| |
| File:Wave Swinger 0.8 Sec SFGAm.JPG|The Whirligig ride during night at [[SFGAm]] at an exposure time of 0.8 Seconds.
| |
| File:Streaks outside Waterloo.jpg|Light streaks outside Waterloo Rail Station in London
| |
| File:Tottenham Ct. Rd. Slow Shutter.jpg|Light streaks on Tottenham Ct. Rd. in London
| |
| File:Tottenham Ct. Rd. Slow Shutter2.jpg|Light streaks on Tottenham Ct. Rd. in London of turning Taxis
| |
| File:Tottenham Ct. Rd. Slow Shutter3.jpg|More Light streaks of a bus in London
| |
| File:Tottenham Ct. Rd. Slow Shutter4.jpg|Bus moving at high speed
| |
| File:Tottenham Ct. Rd. Slow Shutter5.jpg|Slow shutters cannot be handled by hand, a side rail is being used. Bus in London
| |
| </gallery>
| |
| | |
| ==Cinematographic shutter formula==
| |
| {{further|Rotary disc shutter}}
| |
| Motion picture cameras used in traditional [[film]] [[cinematography]] employ a mechanical [[rotary disc shutter|rotating shutter]]. The shutter rotation is synchronized with film being pulled through the gate, hence shutter speed is a function of the [[frame rate]] and [[shutter angle]].
| |
| | |
| Where ''E'' = shutter speed (reciprocal of exposure time in seconds), ''F'' = frames per second, and ''S'' = shutter angle:<ref name=brown/>
| |
| | |
| : <math>E = \frac {F \cdot 360^\circ}{S}</math>, for ''E'' in reciprocal seconds
| |
| | |
| : <math>S = \frac {F \cdot 360^\circ}{E}</math>
| |
| | |
| With a traditional shutter angle of 180°, film is exposed for 1/48 second at 24 frame/s.<ref name=brown>{{cite book | title = Cinematography: Theory and Practice : Imagemaking for Cinematographers, Directors & Videographers | author = Blain Brown | publisher = Focal Press | year = 2002 | isbn = 0-240-80500-3 | url = http://books.google.com/books?id=1JL2jFbNPNAC&pg=PA125&ots=PCXRkW3nIk&dq=cinematography+360+shutter-angle+%22shutter+speed%22&sig=OTsZON3wEZbiNhkgOw8OfZB-amk }}</ref> To avoid effect of light interference when shooting under artificial lights or when shooting television screens and computer monitors, 1/50 s (172.8°) or 1/60 s (144°) shutter is often used.<ref>{{cite web | title = Shutter Speed vs. Shutter Angle | url = http://provideocoalition.com/index.php/freshdv/story/shutter_speed_vs_shutter_angle}}</ref>
| |
| | |
| Electronic video cameras do not have mechanical shutters and allow setting shutter speed directly in time units. Professional video cameras often allow selecting shutter speed in terms of shutter angle instead of time units, especially those that are capable of [[overcranking]] or undercranking.
| |
| | |
| ==See also==
| |
| | |
| {{Commons|Shutter speed}}
| |
| *[[Exposure (photography)|exposure]]
| |
| *[[exposure value]]
| |
| *[[f-number]]
| |
| *[[shutter (photography)|shutter]]
| |
| | |
| ==References==
| |
| | |
| {{reflist|2}}
| |
| | |
| *{{cite book|last=Doeffinger|first=Derek|title=Creative Shutter Speed: Master Your Camera’s Most Powerful Control|publisher=Wiley|year=2009|isbn=978-0-470-45362-9}}
| |
| | |
| {{photography subject}}
| |
| | |
| [[Category:Science of photography]]
| |
It is very common to have a dental emergency -- a fractured tooth, an abscess, or severe pain when chewing. Over-the-counter pain medication is just masking the problem. Seeing an emergency dentist is critical to getting the source of the problem diagnosed and corrected as soon as possible.
Here are some common dental emergencies:
Toothache: The most common dental emergency. This generally means a badly decayed tooth. As the pain affects the tooth's nerve, treatment involves gently removing any debris lodged in the cavity being careful not to poke deep as this will cause severe pain if the nerve is touched. Next rinse vigorously with warm water. Then soak a small piece of cotton in oil of cloves and insert it in the cavity. This will give temporary relief until a dentist can be reached.
At times the pain may have a more obscure location such as decay under an old filling. As this can be only corrected by a dentist there are two things you can do to help the pain. Administer a pain pill (aspirin or some other analgesic) internally or dissolve a tablet in a half glass (4 oz) of warm water holding it in the mouth for several minutes before spitting it out. DO NOT PLACE A WHOLE TABLET OR ANY PART OF IT IN THE TOOTH OR AGAINST THE SOFT GUM TISSUE AS IT WILL RESULT IN A NASTY BURN.
Swollen Jaw: This may be caused by several conditions the most probable being an abscessed tooth. In any case the treatment should be to reduce pain and swelling. An ice pack held on the outside of the jaw, (ten minutes on and ten minutes off) will take care of both. If this does not control the pain, an analgesic tablet can be given every four hours.
Other Oral Injuries: Broken teeth, cut lips, bitten tongue or lips if severe means a trip to a dentist as soon as possible. In the mean time rinse the mouth with warm water and place cold compression the face opposite the injury. If there is a lot of bleeding, apply direct pressure to the bleeding area. If bleeding does not stop get patient to the emergency room of a hospital as stitches may be necessary.
Prolonged Bleeding Following Extraction: Place a gauze pad or better still a moistened tea bag over the socket and have the patient bite down gently on it for 30 to 45 minutes. The tannic acid in the tea seeps into the tissues and often helps stop the bleeding. If bleeding continues after two hours, call the dentist or take patient to the emergency room of the nearest hospital.
Broken Jaw: If you suspect the patient's jaw is broken, bring the upper and lower teeth together. Put a necktie, handkerchief or towel under the chin, tying it over the head to immobilize the jaw until you can get the patient to a dentist or the emergency room of a hospital.
Painful Erupting Tooth: In young children teething pain can come from a loose baby tooth or from an erupting permanent tooth. Some relief can be given by crushing a little ice and wrapping it in gauze or a clean piece of cloth and putting it directly on the tooth or gum tissue where it hurts. The numbing effect of the cold, along with an appropriate dose of aspirin, usually provides temporary relief.
In young adults, an erupting 3rd molar (Wisdom tooth), especially if it is impacted, can cause the jaw to swell and be quite painful. Often the gum around the tooth will show signs of infection. Temporary relief can be had by giving aspirin or some other painkiller and by dissolving an aspirin in half a glass of warm water and holding this solution in the mouth over the sore gum. AGAIN DO NOT PLACE A TABLET DIRECTLY OVER THE GUM OR CHEEK OR USE THE ASPIRIN SOLUTION ANY STRONGER THAN RECOMMENDED TO PREVENT BURNING THE TISSUE. The swelling of the jaw can be reduced by using an ice pack on the outside of the face at intervals of ten minutes on and ten minutes off.
If you have any concerns regarding where and how you can make use of dentist DC, you could contact us at the webpage.