Think of the camera as the human head, and the eye as the lens or the part of the camera that lets light into the camera body. The cornea is the outermost part of the human eye, the cornea is responsible for focusing the ambient light just like a camera lens. This focused light is referred to as a light cone. The light cone is a visual representation of what light looks like when it emanates from a light source and then is constricted to a single point.
The shutter functions much like the human eyelids do with one difference. The eyelids are found before the eyes, the camera's shutter is found before the photosensitive plane which is found after the lens. The eyelids can keep light out or let light into the eyes' inner chamber. They can stay open for an extended amount of time or they can open and close quickly. This action of opening and closing is what allows the light to pass through the eye and eventually enter the body of the human eye; where the light is translated into an image by the brain. The camera’s shutter works in a similar way, when the shutter opens it allows light to enter the camera body allowing light to be captured on to a photosensitive plane which will record the light information. The amount of time the photosensitive plane has to record the information is referred to as the camera's shutter speed.
The aperture acts just like the iris would in the human eye. The iris reacts to the amount of ambient light, the more light that is present the smaller the iris becomes, the less light present the wider the iris becomes. Besides allowing light to enter the eye the size of the iris also helps to focus the light entering the eye. The camera’s aperture works in a very similar way, the aperture is a device that controls how much light enters the cameras body by constricting or expanding the light cone that enters through the cameras front element (lens). This constricting or expanding of light also controls the depth of field. This is done by controlling the size the aperture makes.
This focused light then passes the shutter and falls on to the photosensitive plane of the camera. This photosensitive plane works like the macula of the eye. The macula takes the information and catalogs it into the RGB light color space. This breakdown of information is handled by the rods and cones of the eye. The rods and cones work like the pixels of a digital camera or the photosensitive emulsion of a film camera. The cones catalog the RGB color space and the rod interprets the level of light and darkness of the light source. This is very similar to how the camera uses the ISO, the ISO measures the level of light sensitivity in a given space, the darker the room the higher the ISO in contrast the more light in a room the lower the ISO .
After the information is gathered by both the camera and the eye, the information is passed to a processor in the eye. This is done by the optic nerve, which is then delivered to the occipital lobe, which is located at the lower back part of the brain. The occipital lobe is involved with interpreting the information that is cataloged by the eyes vision. This is similar to how the camera's digital processor deals with the light information, in a digital camera the processor refers to its internal matrix of information that interprets the information. This matrix is essentially a catalog of perfectly balanced images which the camera uses to reference when using the internal light meter.
Nowadays, most digital cameras are small enough to fit in our pockets or are simply on our phones. Over the years, they have also become more cost-effective, allowing more and more people to access this ever-growing medium. Online media has caused the newest social phenomenon, which is the viewing and sharing of images instantly. Also, this has allowed the exchange of new ideas and ways of thinking about photography. Yet the basics of art and photography has not changed all that much.
Photography is undoubtedly one of the most important inventions in history -- it has truly transformed how people perceive the world. Now we can "see" all sorts of things that are many miles -- and years -- away from us. Photography lets us capture moments in time and preserve them for years to come.
The necessary technology that makes all this possible is relatively simple. A still film camera and a digital camera are very similar. Cameras consist of three essential elements: an optical element (the lens), an exposure element (the film or digital sensor), and a mechanical component (the camera body itself). The only trick to photography is understanding how to adjust and combine these elements, so they record a sharp image.
Single-Lens Reflex Camera (SLR)
A modern film camera, more commonly known as a single-lens reflex camera (S.L.R.), uses a mirror and prism system. This system has a moveable mirror behind the lens, reflecting an image up through a five-sided prism (pentaprism). Which then gets reflected into the viewfinder, an area that allows the photographer to compose and frame the image before taking a photograph.
The S.L.R. cameras use Photographic film to capture the image. Photographic film is a strip of plastic that has been coated with photosensitive chemicals that allows the photographer to record the image.
Modern-day film cameras utilize state-of-the-art technology that allows the photographer the freedom to capture images by placing the camera into an automatic setting. The Automatic mode allows the camera to make the decisions for the photographer; this allows the photographer to focus on taking the photo instead of worrying about the technical settings. In the automatic setting, the photographer does not have control of any of the settings. Many professional photographers use manual mode in this mode; the photographer can control all aspects of the image.
Digital Single-Lens Reflex Camera (DSLR)
The world's first digital camera was invented after the first digital photo was already taken. The first digital photo came almost two decades earlier in 1957 when Russell Kirsch made a 176×176-pixel digital image by scanning a photograph of his three-month-old son. The reason the image was made at such a low resolution, was because the computer that was used at the time was not capable of storing a massive amount of information.
The world's first digital camera was invented by Steven Sasson only a few years later. Sasson invented the digital camera while working at Eastman Kodak in 1975. It weighed around 8 pounds and shot a mere 0.01MP
The basics of digital single-lens reflex cameras (DSLR) photography are easy to learn when you appreciate how similar the DSLR is to the S.L.R. cameras. They both control the light in similar ways. Both cameras control the light in the same three ways: Aperture, shutter speed, and ISO. The Aperture is the opening within the lens that controls how much light enters the camera body. The shutter controls the length of time that light comes into the camera body. The ISO controls how sensitive the film or digital sensor is to the available light.
There are many advantages to a DSLR over an S.L.R. camera. One of the advantages is the overall cost of taking images. With a DSLR, you can take multiple images without the substantial cost of buying film and developing the negatives into prints. The next advantage is the ability to see the image right away on the back of the camera's LCD screen or digital viewing screen. This saves time and puts to rest any worries the photographer may have on wondering if the image came out correctly.
Mirrorless Camera (M.I.L.C., DSLM, EVIL)
A mirrorless interchangeable-lens camera (M.I.L.C.), frequently called a mirrorless camera, also called DSLM (digital single-lens mirrorless), and sometimes also called EVIL (electronic viewfinder, interchangeable lens) features a single, removable lens and uses a digital display system rather than an optical viewfinder.
There are many advantages to a Mirrorless Camera. One of the advantages is the overall size of the camera without the need for a mirror. The body of the camera can be slimmer than a traditional camera. In a traditional camera, the mirror needs the extra room to open and close, extending the body of the camera out.
The second advantage of the mirrorless camera is the ability of the lens being closer to the digital sensor. The ability to have the lens closer to the digital sensor allows the camera to have more focus areas. In a traditional DSLR camera, the lens sits further away from the digital sensor narrowing the light cone, thus not filling the digital sensor.