Alfred Stieglitz established the quarterly Camera Work in 1903. Fifty issues were published before it was discontinued in June, 1917. During this time Stieglitz established Camera Work as the most important journal on photography.
Stieglitz published the work of a whole range of photographers in Camera Work, including Lewis Hine, Gertrude Kaswbier, Clarence White, Alvin Longdon Coburnand Edward Steichen. In 1913 Alfred Stieglitz devoted a double issue of the journal to Steichen's photographs. He wrote in the magazine: "Nothing I have ever done has given me quite so much satisfaction as finally sending this number out into the world." The last edition featured the work of Paul Strand, the man Stieglitz considered the most important photographer working at that time.
A Brief History of the Camera Flash, From Explosive Powder to LED Lights
The first known photograph was captured in 1826 when light reacted with a particular type of asphalt known as Bitumen of Judea. Since that first natural light photo, photographers have introduced artificial flash lighting to photos through all kinds of different ways. In this post, we’re taking a look at a brief history of the camera flash — from its humble beginnings with explosive powder and burning metal up through the latest LED lights — to see how far it has come.
If you have watched any movies depicting life in the nineteenth century, you may have witnessed a photographer holding a tray that suddenly produces a bright flash and a loud bang. In some slapstick comedies, a cloud of smoke might then dissipate showing the photographer standing with a blackened face. This technique utilized what we now call flash powder.
Flash powder is a composition of metallic fuel and an oxidizer such as chlorate. When the mixture is ignited, it burns extremely quickly producing a bright flash that can be captured on film. Before being used for photography, flash powder was commonly used in theatrical productions and within fireworks — a practice we continue to this very day.
Needing to ignite flash powder by hand was an extremely dangerous endeavor that could seriously injure the photographer and those in close proximity. As a result, a safer solution had to be devised that could ignite while reducing the chance one’s face might get burned. A bit of improved safety came from the flash-lamp that was designed in 1899.
Joshua Lionel Cowen, an inventor best known for his Lionel model railroads and toy trains, and photographer Paul Boyer introduced the flash lamp right before the turn of the twentieth century. The design had a trough that would hold flash powder to then be ignited via electricity from a dry cell battery.
A Victor flash lamp from 1909. Photo by Race Gentry
The flash lamp was typically connected to the shutter of camera boxes, allowing for the flash to be activated as the photographer snapped the photograph. The flash mechanism could be placed on a tripod away from the camera for activation. One could also connect multiple flash lamps to be ignited at the same time when in a series.
An alternative solution, developed by Bunsen and Roscoe, was to ignite a magnesium ribbon that reproduce a light temperature similar to daylight while burning. Photographers would cut the strip of metal dependent on the duration of their exposure then ignite it to illuminate their subjects. Despite Bunsen and Roscoe’s idea being around first, flash powder was more widely adopted by photographers looking for a bit of artificial light.
A Victor flash lamp advertisement. Photo by Jussi
While the flash lamp was able to make the practice of flash photography a bit safer, it was still very dangerous when compared to today’s standards. Photographers were still injured in the practice and, in some cases, died while attempting to prepare the powder for usage. Luckily, a new solution was just around the corner.
A photographic flash bulb. Photo by Gotanero
In 1927, the first flash bulbs were produced by General Electric (some argue that they were initially made by the Vacublitz company in Germany). Instead of lighting magnesium powder in the open air, flash bulbs were closed lamps that contained a magnesium filament along with oxygen gas. Initial bulbs were designed out of glass, but they were later switched to plastic when it was discovered that the magnesium’s ignition could break the bulb.
Of course, flash bulbs were far from the perfect solution: the bulbs tended to be incredibly fragile and could only be used once. Also, the bulbs were typically too hot to handle after they were fired. Manufacturers did eventually replace the magnesium with brighter burning zirconium for a more powerful flash.
Some interesting quirks of flash bulbs include the fact that the time needed to reach full brightness and the maximum duration of the flash were both longer than the electronic flash units of today. As a result, cameras with flash synchronization capabilities typically fired the flash bulb before opening the shutter to expose the film.
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Flashcubes And Flipflash
As you might expect, constantly replacing flashes can become a bit annoying for the average photographer. As a result, Kodak introduced the Flashcube in the late 1960s. The flashcube contained four different flashbulbs for usage. Simply snap a photograph then rotate the cube to use the next flashbulb. Manufacturers quickly took note of this idea and began creating their own compact solutions.
The first non-Kodak solution was the General Electric Flipflash, which arranged eight to ten flashbulbs in two rows. A photographer could plug in the cartridge, fire four to five shots, then flip the unit over to access the other four to five bulbs. Other companies including Phillips, Polaroid, and Sylvania also released their own versions of the Flipflash while carefully navigating around General Electric’s product patents.
A Flipflash camera flash. Photo by Windell Oskay.
What the industry needed, however, was a flash that wouldn’t die after being fired once. Back in 1931, Electrical Engineering professor Harold Egerton began work on the first electronic flash tube. It took a good amount of improvement and decreased costs for the devices to finally become popular in the second half of the twentieth century.
Electronic flashes would come to use a capacitor to store power for later use. When an electronic flash is triggered, the capacitor releases its energy through a flashtube, which is filled with gas that produces an intensely bright light for a very short time. Excellent synchronization, along with the ability to change intensity on the fly, made electronic flashes the dominant solution while pushing flashbulbs into obsolescence.
Today, we use electronic flashes within studios and on-the-go to illuminate our subjects and scenes. Tubes within electronic flashes are typically filled with xenon gasses and have a relatively long lifespan before needing to be replaced with an entirely new unit.
With the advent of wireless technology, multiple flashes can also be placed off camera and synchronized without the necessity of a complicated setup. We also now have high-speed flashes that can discharge light in extremely short amounts of time.
Unless you are carrying around a Nokia Lumia 1020, then your smartphone most likely does not contain a xenon flash. Current smartphones use LED flashes as a source of light when photographing in low light conditions.
LEDs are nowhere near as powerful as xenon flashes, but they are a lower voltage and minuscule — perfect for the pocket. Some companies (i.e. Apple and Nokia) have integrated dual color LED flashes into smartphones to help produce more natural skin tones.
And there you have it: a brief history of the camera flash, from early its origins until now!
Image credits: Header illustration based on photo by Dan Eckert, flash powder photo by Conejo de
In the early 1800s, the camera obscura had become a portable, light-tight box that contained materials and chemicals that would momentarily record the image through the lens. Cameras created in the 1800s were often crafted for looks as well as functionality. For instance, fine woods were used with brass fixtures to showcase the equipment. Wood had the advantage over metal as it was lighter and the camera could be made larger, which would give the photographer more movement and extension. The wood was also exceptional for dampening vibration, which could affect a metal camera and blur the picture. On the other hand, the metal cameras had the advantage of less flexibility for long extensions. The metal cameras could be knocked over with little damage, while the wooden cameras could be shattered if they hit the floor.
In 1816, Joseph Niépce and his Brother Clyde successfully produced a paper negative from the image. When they sandwiched this negative with another piece of sensitized paper, a positive image would appear. Unfortunately, there still was no way of making these images permanent.
Niépce decided to use pewter plates coated with bitumen of Judea, which was an asphaltic varnish that hardened when exposed to light. He originally exposed these plates to some light through an oiled etching on a piece of paper, and washed the plates with a solvent after exposure to remove the hardened parts of the image. This created a positive representation of the etching on a metal plate, which was called a heliograph. The plate was then etched with acid, inked, and printed.
Niépce decided to place the light-sensitive plates within a camera and expose them, which produced the first permanent photographs around 1826. The camera needed about eight hours for proper exposure. These positive images were too faint for repeated printing, so the photographs were one-of-a-kind. This process did not use the light sensitive silver salt and could reproduce the image in light and dark tones with no color. He continued to attempt to improve his process.
Another Frenchman, Louis Jacques Mandé Daguerre used the camera for his sketches and experimenting with the light-sensitive silver salts at around the same time as Niépce's experiments. Eventually, Niépce and Daguerre worked together to further their research. Daguerre finally used a copper sheet plated with silver that had been polished and fumed with a vapor of iodine to produce the light sensitive silver iodide on the plate's surface. This plate was then placed into the camera and exposed to the image. The plate was treated after exposure with the fumes from heated mercury to produce a stronger, more visible image, which was then fixed with salt water. This produced a silvery, delicate, monochromatic image that was unique. Daguerre called his invention the daguerreotype.
Giroux Alphonse Daguerreotype Camera
Daguerre's invention was brought into the public eye at the Academy of Sciences in 1839, and the French government began to provide pensions to Daguerre and Niépce in exchange to the rights for the invention. People were entranced with the camera and the images it produced, and it even caused French painter Paul Taylor Roche to declare that painting was dead for all time. Daguerre designed the first commercially manufactured camera in 1839, which was made by Alfonse Giroux in Paris. It consisted of a double box camera based on the experimental work conducted by Daguerre. This view camera featured an achromatic 15-inch F/15 landscape lens that was manufactured by a Parisian instrument and optician maker named Chevalier.
In 1839, William Henry Fox Talbot of England learned of the new photographic technology. He had begun to experiment with these processes in 1834, and learning about Niépce and Daguerre's invention, brought his own to the Royal Institution and the World Society by the end of that January. He used paper that had been sensitized with silver chloride, upon which he placed objects. These were exposed to light in what are now called photograms. Later, he exposed the paper to an image in the camera to produce a negative image that he fixed by bathing the paper in salt water. He would then create a positive image by placing it against a second sheet of sensitized paper and exposing both to light using the contact printing method. Talbot continued to work with his camera to invent the calotype, and during this time he sensitized paper with silver iodide. Exposure to light would produce a latent image however, he learned this negative image could become visible with a chemical development in a second wash of gallo-nitrate of silver. The print was then fixed with a solution of potassium bromide. The development of this latent image resulted in less exposure time. The negative image was then contact printed to another sensitized paper sheet to produce a positive image.
Over the next several years, other inventors attempted to improve the photographic process. One English man, Sir John Herschel, discovered sodium thiosulfate provided a true fixative for the images. He originally misidentified the substance as sodium hyposulfite, and nicknamed the substance hypo. This term is still used today for photography fixative.
Camera access history log
Hi Stefan. I'm Greg, an installation specialist, 10 year Windows MVP, and Volunteer Moderator here to help you.
There's no log but you can see which apps are being allowed to access the camera here:
Also more about ways Microsoft provides to restrict the camera here:
I hope this helps. Feel free to ask back any questions and keep me posted. If you will wait to choose if I solved your problem, I will keep working with you until it's resolved.
Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.
Millions helped via my tutorials and personally in forums for 12 years. Now an Independent Advisor.
30 Movies With The Most Brilliant Camera Work
Cinema is the only art form capable of utilizing and combining all other arts, and in such inspiring ways that it can produce a new way of complete human expression ergo a fresh, and “sui generis” art itself. However, as in every art form, to achieve a confirmed or acclaimed artistic status is not a matter of self-declaration, but one of specific assets. Perhaps the most critical of all those assets in film is none other than the camerawork.
The camera placement and movement is one of the most crucial aspects in every film production. It represents the overall vision of the director, the skill of the director of principal photography, and their ongoing collaboration throughout the filmmaking process. Since the beginning of feature films in the first decade of the 20th century, many of the pioneering techniques have been used extensively, maximizing not only the possibilities of each era’s camera technologies, but also the level of artistry in motion pictures.
Tracking shots, crane shots, multiple cameras shooting the same scene from different angles, “Dutch angles”, long takes, the use of deep focus, the use of wide-angle and zoom lenses, and intentionally unsteady shots through a hand-held camera, are all different ways of making a film more beautiful, and more rich in meanings and symbolisms. Add to that the benefits of post-production (editing, special effects, soundtrack), and it is quite clear that cinema is limitless regarding its creative potency.
Any filmmakers who have mastered all those classic camera techniques mentioned above, and are lucky enough to have a well-written screenplay on their hands, plus an efficient crew to surround them, meet the requirements to make a good film.
But to make a great film, you need a bit of that extra magic that separates the true visionaries of the medium (those who challenge the audiences to follow them in their often uncompromising and non-mainstream cinematic ventures) from the dexterous craftsmen (those who depend on their technical expertise in order to impress the largest possible amount of viewers, incorporating the “entertainment” factor into their work).
As Aristotle quotes, “the aim of art is to represent not the outward appearance of things, but their inward significance”. The following list is a selection of 30 movies (please do not pay much attention to their order, it is of secondary importance), from different eras, genres and cinema movements, which fulfill this aim by relying heavily on their brilliant camerawork. These are not necessarily revolutionary movies in terms of technological breakthrough, but they are in terms of artistic virtuosity.
Directed by Fernando Meirelles, & Kátia Lund
Cinematography by César Charlone
One of the most poignant crime films of the 21st century thus far, “City of God” is a coming-of-age story which manages to point out the unstrained social commentary surrounding the recent history of Brazil’s organized crime.
The subjective narrative, freeze frames and sweeping scene shots are clearly influenced by the cinematography in Martin Scorsese’s “Goodfellas” (although director Fernando Meirelles uses a non-linear narrative style, plus many amateur actors from the favelas, which are also key elements for the depiction of the disordered lifestyle of the gangs), but César Charlone’s camera has a life of its own, fully dependent on the era in which the events take place lively and furious in the late 60s, more static and character-centered during the majority of the 70s, and documentary-like in the protagonists’ more mature phase (the 80s).
Directed by Jean-Luc Godard
Cinematography by Raoul Coutard
A French New Wave gem, “Band Of Outsiders” is quite more accessible than Jean-Luc Godard’s previous contributions to the movement (“Breathless”, “Contempt”, “Vivre Sa Vie”), mainly because of the amusing narrative form, and the charming heist/love triangle plot.
For most of its running time, it is a carefree inner-city road movie, where the camera focuses on the “outsiders” while they drive, chat, dance and run all over Paris (there are three particular scenes which remain highly influential – if you are familiar with the dance scene in “Pulp Fiction”, you will definitely see the connection, in terms of style), providing a vibrant portrayal of the city life, and paying tribute to youthfulness at the same time.
Directed by Akira Kurosawa
Cinematography by Asakazu Nakai
This heroic samurai gathering is one of the most respected and influential movies of all time, and one of the few really convincing slices of life from previous centuries (Kurosawa and Tarkovsky are probably the greatest ever in that department).
There is no particular secret behind the film’s success, other than the creator’s persistence to take the most out of every situation. This translated to a constructed set on location from the start, in order to get the best performances out of his cast, and the innovative (at the time) use of multiple cameras for the action sequences.
Directed by Ken Loach
Cinematography by Chris Menges
“Kes” is arguably the best British drama of all time, the finest of all Ken Loach’s social realist films, and quite possibly the most beautiful film inspired by Italian Neorealism.
Chris Menges employs some long-distance shots to take advantage of South Yorkshire’s contrasting scenery. At one end, there is the beautiful green countryside (the place where a boy like Billy – the main star of the film – can enjoy some peace, away from the bullying at school and the quarrels at home), while at the other end, the quiet but depressing little towns, with a clear view of the nearby mines and industrial establishments (the most probable life destination for all the youngsters of the area). These images set the tone for what is about to come, while the use of non-professional actors speaking the Yorkshire dialect gives a documentary-like flavor to the film.
Directed by Francis Ford Coppola
Cinematography by Vittorio Storaro
On the surface, this epic adventure may look like over-the-top war poetry, but in reality it is a thorough study of human nature.
Coppola (together with John Milius who co-wrote the screenplay) used the Vietnam War as the vehicle for his story, and shot the film in the Philippines. For the biggest part of the movie, the camera moves slowly and serves as Captain Willard’s point of view. His river journey into the jungle in order to spot and terminate Colonel Kurtz’s unauthorized operations, visually echoes Lupe de Aguirre’s search for El Dorado (Herzog’s “Aguirre, Wrath Of God” was a major influence on Coppola), but there are also a few surreal modern war sequences happening along the way.
25. Shadows Of Forgotten Ancestors (1965)
Directed by Sergei Parajanov
Cinematography by Viktor Bestayev, & Yuri Ilyenko
A “Romeo & Juliet” type of story, “Shadows Of Forgotten Ancestors” is a film with strong naturalistic elements and symbolism (one of the main reasons behind Parajanov’s condemnation to artistic death inside the Soviet Union).
The frenetic camera movement blends with intense colors, costumes and the unique folk music of the Carpathian Mountains, and the result is a sublime celebration of the Hutsul culture. This is a film that could have been made without any dialogue the camera does the speaking, as we are witnessing a pure cinematic explosion of genius.
Directed by Max Ophüls
Cinematography by Philippe Agostini, & Christian Matras
“Le Plaisir” is an anthology of three dramatic short stories all associated with pleasure, and a typical Ophüls masterpiece.
In each story, there are a number of virtuosic dolly shots of the basic characters’ gatherings, which give a romantic tone to the whole project. As for the first story in particular, though it’s the smallest one duration-wise, it remains astonishing even by today’s standards. It begins with extraordinary “Dutch angle” shots, which pave the way for the splendid long take of the dance hall scene, and the rest is history.
“Down by Law” is a black and white cult comedy classic by one of the most original American indie filmmakers, who was fortunate enough to have Robby Müller behind the camera, and a still-unknown Roberto Benigni in front of it (next to Tom Waits and John Lurie) speaking English. The result was a rare mix of surrealist humor and downbeat beauty.
Müller used slow-moving camerawork and natural day and night lighting, which were perfect fits for the three loners of the movie, the empty streets of New Orleans, and Waits and Lurie’s hypnotic soundtrack (both the composers and stars of the film).
Directed by Terrence Malick
Cinematography by Néstor Almendros, & Haskell Wexler
A period romantic drama set in the Texas Panhandle (the actual shooting location was the ghost town of Whiskey Gap, Alberta, Canada) and narrated from a little girl’s point of view, “Days Of Heaven” is one of the most notable examples of American arthouse filmmaking.
The images that appear onscreen are some of the most captivating ones in film, and Malick’s stubbornness to shoot daily during the “magic hour” (20-25 minutes after sunrise, or before sunset) was the main reason behind the artistic success of the movie.
Directed by Paul Thomas Anderson
Cinematography by Robert Elswit
A gripping coming-of-age story of fame and decadence, this movie offered originality and a brilliant ensemble cast when it was released 18 years ago. Most of all, it marked the first big breakthrough for one of the most important cinema voices of our time.
Modern Digital Video Cameras
Professional video cameras have come a very long way since the introduction of the 1.4-megapixel digital camera. In the early 2000s, Sony developed the first high definition digital video cameras. Today, high-resolution digital video is no longer confined to the domain of the television studio. High-end professional digital video cameras are used for independent films, web series and hobbyist purposes.
In the hand-held realm, the familiar camcorder of the 1980s underwent a smoother evolution to digital. It wasn’t until 2003 that Sony introduced the first digital video camcorder that eliminated the need of tape entirely.
These hand-held digital video cameras have found use in projects from home movies to professional film. Celebrated horror director Michael Almereyda’s 1994 film, Nadja, notably uses an early digital video camera manufactured by Fisher-Price in certain sequences for its gritty, low-resolution effect. These hand-hend devices have also contributed greatly to live journalism, as well as journalism’s casual cousin, “vlogging,” which is live video blogging on websites like YouTube.
How does a camera work? A beginner&rsquos simple guide on how to use a camera
Everyday, 1.8 billion photographs are shared on the web, pausing life and turning moments into digital pixels of information. But how does a camera take something that we see and turn it into digital pixels? How are cameras able to freeze time?
Photography is actually just as much a science as it is an art &mdash yet a large majority don&rsquot realize what happens every time they push the camera&rsquos button or open a smartphone camera app. So how does a camera work? Here&rsquos what happens every time you press that button &mdash and how to use a camera to take better pictures.
The Basics: Light and How The First Cameras Worked
Imagine you are standing in the middle of a room with no windows, doors or lights. What do you see? Well, nothing because there&rsquos no light. Now imagine you pull out a flashlight and turn it on. The light from the flashlight moves in a straight line. When that beam of light hits an object, the light bounces off that item and into your eyes, allowing you to see whatever is inside the room.
All light behaves just like that flashlight &mdash it travels in a straight line. But, light also bounces off of objects, which is what allows us to see and photograph objects. When light bounces off an object, it continues to travel in a straight line, but it bounces back at the same angle that it comes in at.
That means light rays are essentially bouncing everywhere in all kinds of different directions. The first camera was essentially a room with a small hole on one side wall. Light would pass through that hole, and since it&rsquos reflected in straight lines, the image would be projected on the opposite wall, upside down. While devices like this existed long before true photography, it wasn&rsquot until someone decided to place material that was sensitive to light at the back of that room that photography was born. When light hit the material, which through the course of photography&rsquos history was made up of things from glass to paper, the chemicals reacted to light, etching an image in the surface.
How does a camera work? The Lens
Since that first camera did not capture very much light, it actually took eight hours to take a single photograph. The image was also quite blurry. So how are we able to take sharp images in milliseconds today? A camera lens.
While light bounces off of objects, it can also pass through objects &mdash but, when it does, it can actually change direction. A camera lens takes all the light rays bouncing around and uses glass to redirect them to a single point, creating a sharp image.
When all of those light rays meet back together on a digital camera sensor or a piece of film, they create a sharp image. If the light doesn&rsquot meet at the right point, the image will look blurry or out-of-focus. A lens&rsquos focusing system moves the glass piece closer or farther from the sensor or film, allowing the photographer to adjust the lens so that the object is sharp.
Distance also plays a role in how camera lenses are able to zoom in. When the front piece of glass moves farther away from the camera sensor, objects become closer. Focal length is the measurement of the distance between where the light rays first hit the lens and where they reach the camera sensor. For example, on a lens with a 300mm focal length, the light takes 300 mm to be directed back into a sharp point on the camera sensor. A 300mm lens is considered a telephoto, or a lens that&rsquos able to bring far objects close.
How does a camera work? Film and digital sensors
A camera lens collects and focuses the light &mdash but how is that information recorded? Historically, photographers were also chemists of sorts. Film is made up of light sensitive materials. When those materials are hit with light from the lens, they captured the shape of the objects and details like how much light is coming off of them. In the dark room, the film that was exposed to the light is again put in a series of chemical baths to eventually create the image.
So then how do digital cameras work? While the lenses, techniques and terms are the same, a digital camera&rsquos sensor more closely resembles a solar panel than a strip of film. Each sensor is divided up into millions of red, green and blue pixels (i.e. megapixels). When light hits the pixel, the sensor converts it into energy and a computer built inside of the camera reads just how much energy is being produced.
Measuring how much energy each pixel has allows the sensor to determine what areas of the image are light and dark. And since each pixel has a color value, the camera&rsquos computer is able to estimate the colors in the scene by looking at what other nearby pixels registered. Putting the information from all the pixels together, the computer is able to approximate the shapes and colors in the scene.
If each pixel is gathering light information, then camera sensors with more megapixels are able to capture more detail. That&rsquos why manufacturers often advertise a camera&rsquos megapixels. While that&rsquos true to some extent, the size of the sensor is also important. Larger sensors will gather more light, making them better performers for low light scenes. Packing lots of megapixels into a small sensor actually makes the image quality worse, because those individual pixels are too small.
Putting it into practice: How to use a camera
All modern cameras use a lens and sensor (or film) to record an image. But why then, can two people take a photograph of the same scene and end up with very different results? A camera is a bit more than a lens and a sensor, and adjusting those extra elements changes the way the final image looks.
One way that images become unique is through composition. A camera&rsquos lens is incapable of seeing everything &mdash composition is simply a term that is used to describe what the photographer chooses to leave in, and what they chose to leave out. Adjusting composition is often as easy as moving around in a scene &mdash think moving forward or backwards as well as side to side or even kneeling or standing on a chair. Small changes in the camera&rsquos position can make a big impact on the photograph.
Lenses can also help alter a photograph&rsquos composition. With zoom lenses, the glass is assembled in a way that allows the user to adjust how close or far away the item appears. On a compact camera, zoom is often done with a small toggle at the top of the camera, while DSLR and mirrorless lenses have a twist control around the lens. Zoom is an excellent tool for cropping out distracting objects.
Another important aspect of photography is exposure, or how light or dark the image is, and it relies on a number of different factors that, put together, determine how much light is recorded.
Digital cameras have a built-in meter that measures the amount of light in a scene. While on auto, the camera&rsquos computer chooses the correct exposure. While auto mode is not perfect and doesn&rsquot allow you to customize the final look of the photo, you can shoot a properly exposed image (most of the time) by selecting &ldquoauto&rdquo mode inside the camera&rsquos menu or, on more advanced cameras, a mode dial at the top of the camera.
Newbie photographers can still adjust the exposure without learning manual modes through exposure compensation. This feature simply lightens and darkens the image. On advanced cameras, exposure compensation is often adjusted by pressing the button with a + and - sign on it and turning the dial near your right thumb. The feature isn&rsquot exclusive to advanced cameras though &mdash on an iPhone, you can tap the screen, then touch the sun icon that appears and drag your finger up and down.
Once you&rsquove chosen an exposure mode (likely auto for new photographers) and determined what to include in the composition, just press the button at the top right of the camera, right? Yes &mdash and no.
Pressing the top button (the technical term is shutter release) all the way will take a photograph, but pressing it halfway will focus the shot. Looking through either the hole at the top of the screen (which is called a viewfinder) or at the camera&rsquos LCD screen, press the shutter release halfway. Check and see that what you want to be in focus (the &ldquosubject&rdquo) is actually in focus, then push the shutter release all the way to take the photograph.
Using a digital camera, the photograph you just took will appear on the LCD screen. If it doesn&rsquot pop up automatically, press the button with the play symbol to bring up the photos you shot &mdash you can use the arrow keys to flip through them. Thanks to that digital technology, you can view your images and reshoot them if you don&rsquot like the composition or need to adjust the exposure compensation
While technology allows you to take a photograph with the touch of a button, it wasn&rsquot always that way. Cameras collect and record light using some pretty neat science and advanced technology. The time machine may be science fiction, but the camera can freeze memories to last forever.
Want to do more than just point and shoot? Own a DSLR yet you&rsquore still stuck on auto mode? Learn how to use manual modes to take your photography to the next level.
How Cameras Work
Photography is undoubtedly one of the most important inventions in history -- it has truly transformed how people conceive of the world. Now we can "see" all sorts of things that are actually many miles -- and years -- away from us. Photography lets us capture moments in time and preserve them for years to come.
The basic technology that makes all of this possible is fairly simple. A still film camera is made of three basic elements: an optical element (the lens), a chemical element (the film) and a mechanical element (the camera body itself). As we'll see, the only trick to photography is calibrating and combining these elements in such a way that they record a crisp, recognizable image.
There are many different ways of bringing everything together. In this article, we'll look at a manual single-lens-reflex (SLR) camera. This is a camera where the photographer sees exactly the same image that is exposed to the film and can adjust everything by turning dials and clicking buttons. Since it doesn't need any electricity to take a picture, a manual SLR camera provides an excellent illustration of the fundamental processes of photography.
The optical component of the camera is the lens. At its simplest, a lens is just a curved piece of glass or plastic. Its job is to take the beams of light bouncing off of an object and redirect them so they come together to form a real image -- an image that looks just like the scene in front of the lens.
But how can a piece of glass do this? The process is actually very simple. As light travels from one medium to another, it changes speed. Light travels more quickly through air than it does through glass, so a lens slows it down.
When light waves enter a piece of glass at an angle, one part of the wave will reach the glass before another and so will start slowing down first. This is something like pushing a shopping cart from pavement to grass, at an angle. The right wheel hits the grass first and so slows down while the left wheel is still on the pavement. Because the left wheel is briefly moving more quickly than the right wheel, the shopping cart turns to the right as it moves onto the grass.
The effect on light is the same -- as it enters the glass at an angle, it bends in one direction. It bends again when it exits the glass because parts of the light wave enter the air and speed up before other parts of the wave. In a standard converging, or convex lens, one or both sides of the glass curves out. This means rays of light passing through will bend toward the center of the lens on entry. In a double convex lens, such as a magnifying glass, the light will bend when it exits as well as when it enters.
This effectively reverses the path of light from an object. A light source -- say a candle -- emits light in all directions. The rays of light all start at the same point -- the candle's flame -- and then are constantly diverging. A converging lens takes those rays and redirects them so they are all converging back to one point. At the point where the rays converge, you get a real image of the candle. In the next couple of sections, we'll look at some of the variables that determine how this real image is formed.
We've seen that a real image is formed by light moving through a convex lens. The nature of this real image varies depending on how the light travels through the lens. This light path depends on two major factors:
The angle of light entry changes when you move the object closer or farther away from the lens. You can see this in the diagram below. The light beams from the pencil point enter the lens at a sharper angle when the pencil is closer to the lens and a more obtuse angle when the pencil is farther away. But overall, the lens only bends the light beam to a certain total degree, no matter how it enters. Consequently, light beams that enter at a sharper angle will exit at a more obtuse angle, and vice versa. The total "bending angle" at any particular point on the lens remains constant.
As you can see, light beams from a closer point converge farther away from the lens than light beams from a point that's farther away. In other words, the real image of a closer object forms farther away from the lens than the real image from a more distant object.
You can observe this phenomenon with a simple experiment. Light a candle in the dark, and hold a magnifying glass between it and the wall. You will see an upside down image of the candle on the wall. If the real image of the candle does not fall directly on the wall, it will appear somewhat blurry. The light beams from a particular point don't quite converge at this point. To focus the image, move the magnifying glass closer or farther away from the candle.
This is what you're doing when you turn the lens of a camera to focus it -- you're moving it closer or farther away from the film surface. As you move the lens, you can line up the focused real image of an object so it falls directly on the film surface.
You now know that at any one point, a lens bends light beams to a certain total degree, no matter the light beam's angle of entry. This total "bending angle" is determined by the structure of the lens.
In the last section, we saw that at any one point, a lens bends light beams to a certain total degree, no matter the light beam's angle of entry. This total "bending angle" is determined by the structure of the lens.
A lens with a rounder shape (a center that extends out farther) will have a more acute bending angle. Basically, curving the lens out increases the distance between different points on the lens. This increases the amount of time that one part of the light wave is moving faster than another part, so the light makes a sharper turn.
Increasing the bending angle has an obvious effect. Light beams from a particular point will converge at a point closer to the lens. In a lens with a flatter shape, light beams will not turn as sharply. Consequently, the light beams will converge farther away from the lens. To put it another way, the focused real image forms farther away from the lens when the lens has a flatter surface.
Increasing the distance between the lens and the real image actually increases the total size of the real image. If you think about it, this makes perfect sense. Think of a projector: As you move the projector farther away from the screen, the image becomes larger. To put it simply, the light beams keep spreading apart as they travel toward the screen.
The same basic thing happens in a camera. As the distance between the lens and the real image increases, the light beams spread out more, forming a larger real image. But the size of the film stays constant. When you attach a very flat lens, it projects a large real image but the film is only exposed to the middle part of it. Basically, the lens zeroes in on the middle of the frame, magnifying a small section of the scene in front of you. A rounder lens produces a smaller real image, so the film surface sees a much wider area of the scene (at reduced magnification).
Professional cameras let you attach different lenses so you can see the scene at various magnifications. The magnification power of a lens is described by its focal length. In cameras, the focal length is defined as the distance between the lens and the real image of an object in the far distance (the moon for example). A higher focal length number indicates a greater image magnification.
Different lenses are suited to different situations. If you're taking a picture of a mountain range, you might want to use a telephoto lens, a lens with an especially long focal length. This lens lets you zero in on specific elements in the distance, so you can create tighter compositions. If you're taking a close-up portrait, you might use a wide-angle lens. This lens has a much shorter focal length, so it shrinks the scene in front of you. The entire face is exposed to the film even if the subject is only a foot away from the camera. A standard 50 mm camera lens doesn't significantly magnify or shrink the image, making it ideal for shooting objects that aren't especially close or far away.
A camera lens is actually several lenses combined into one unit. A single converging lens could form a real image on the film, but it would be warped by a number of aberrations.
One of the most significant warping factors is that different colors of light bend differently when moving through a lens. This chromatic aberration essentially produces an image where the colors are not lined up correctly.
Cameras compensate for this using several lenses made of different materials. The lenses each handle colors differently, and when you combine them in a certain way, the colors are realigned.
In a zoom lens, you can move different lens elements back and forth. By changing the distance between particular lenses, you can adjust the magnification power -- the focal length -- of the lens as a whole.
More About This Page:
How does this test work? How does it test webcam capabilities?
In this test your browser asks for permission to see the output of your computer&aposs webcam, or the browser on your phone asks for permission to see the output of the camera - and the output is then transferred to your screen.
That makes it easy - if you see the cam video then you know it&aposs working and connected.
As was mentioned above, everything that happens happens in your computer and no information is being sent to our servers. We care about your privacy.
Why do you only test FPS and the camera&aposs video output? My webcam can also record sound.
True, some cams have a microphone built-in as well. But since that is not the case for everybody (and also for historic reasons), we decided to separate the audio and video to two different tests. If you&aposre looking to check if the audio of your webcam works, please check our mic test page.
Speaking of which. What exactly is FPS, and why is it important?
FPS is the number of frames, or images, that your webcam is taking and transmitting every second. This number is affected by the type of webcam that you have, and also by the speed of your computer and the number of tasks that it is engaged in at a given moment.
FPS matters because the higher this number is the more life-like and real the resulting video looks. We are used to seeing movies in the cinema and TV shows displayed at around 24-30 FPS. Generally the FPS of television is higher than that of the cinema.
So if, let&aposs say, you&aposre using Skype and the FPS your camera is recording is lower than 24, then that means that the image is going to look a little stuttery to the other side.
A number significantly higher than 30, meanwhile, just means that the video will be more fluid, more lifelike. This fluidity might seem a little odd to our eyes which are accustomed to 24-30 FPS, but generally a higher FPS count is a good thing. It will just look a little less "cinematic", and a little more "daily soap opera".
What do I do if after all the trouble-shooting stages my webcam still isn&apost working?
To understand whether the problem is with the webcam or with your computer, we would advise that you try your webcam on a different computer. Also, if you have access to one, try a different camera at your own computer.
This should leave you with a better understanding on what&aposs working and what isn&apost, and what needs to be fixed.
If you think the camera isn&apost working (you tried it on two computers and it didn&apost work), then contact the support staff of the camera&aposs brand.
If the camera is working on a different computer but isn&apost working on yours - then it means there&aposs probably a software issue with your computer. You can try contacting us and we&aposll try to help, hopping on a general tech support forum on the internet, or calling a technician.
An Interesting Side-Note
The red-eye effect happens because the light of the flash occurs too fast for the pupil to close and much of the very bright light from the flash passes into the eye through the pupil. The light then reflects off the back of the eyeball and out through the pupil.
The camera records this light. Since the light goes through the blood in the choroid which nourishes the back of the eye, the color of the eye is red, hence this annoying effect everyone is aware of. Various techniques are available to combat the problem today, but it's interesting to know why it occurs!