Saturday, August 22, 2009

What is a Camera?

So what is a camera anyway? Your camera is a tool. No different than a wood carver's chisels. The chisels do not make finely crafted artwork, the wood carver does. It is the same way with your camera. The camera does not make the photograph, you do. Never allow yourself to feel like the camera is in control. The camera is your tool and you must use it as a tool.

Broken down to its essential elements, the camera is a box that controls the amount of light that reaches a piece of light sensitive film or other surface inside. The original cameras did not even have a glass lens. The first cameras used a tiny hole in the front of the box to allow in light and to focus the image onto the viewing surface. This is the same principle as when children punch a pinhole into a piece of paper in order to watch a solar eclipse projected through the pinhole and onto the ground.

Today's cameras use glass lenses to focus and capture light much more quickly and to allow us to magnify images. Film is much more sensitive and finely detailed than the first film surfaces and now we also have digital sensors that sometimes take the place of film. Today's cameras also have shutters that control the light from reaching the film or sensor with the touch of a button and have powerful flashes to help illuminate scenes. The camera has come a long way from its humble beginnings, but it is still just a box that controls the amount of light that reaches a piece of film.

Body: The camera body is the most basic part of a camera. It is the box that holds the film and the camera controls. The lens is either built-into the body or attaches to the body. The body also houses a battery that powers the shutter, flash, light meter, and other controls. There are generally rings to connect a strap to the camera for easy carrying as well.

Viewfinder: The viewfinder is the hole in the back of the camera that a photographer looks through to aim the camera. Some viewfinders use a mirror inside the camera to look through the lens (TTL). Other viewfinders are simply holes through the body of the camera. Viewfinders that look through the lens (TTL) allow the photographer better accuracy when composing their images.
Shutter Release: The shutter release is a button that raises a shutter inside the camera for a specified amount of time to allow light to expose the film. In a SLR camera, this button also raises a mirror that allows the photographer to use the viewfinder to look through the lens itself. Many SLR cameras also allow a remote release of the shutter via a cable or IR remote.

In automatic cameras, the shutter release also causes the film to advance to the next exposure. In manual cameras, there is a "film advance lever" that must be turned in order to advance the film and the exposure counter.



Optical Lens: On the front of a camera lens there is a glass lens that focuses light into the camera body and onto the film. Inside the lens body, there are several other optical lenses that further refine the image. These lenses are sometimes called "elements".
Filter Threads: In front of the first optical lens, there is a small ring with screw threads cut into it. These screw threads allow for filters and other accessories to be easily attached to the front of the lens. Each lens carries a second mm rating that tells the diameter of this front attachment point.

Focusing Ring: Each lens has a focusing ring. This is a section of the lens that rotates to allow the photographer to focus the image. On automatic cameras, this ring is moved by a small motor within the lens whenever the photographer presses the shutter release button halfway down. These rings are usually marked with guide numbers showing how far away a subject is when focused.

Focal Length Ring: Each lens that has zoom capability has a focal length ring. This ring allows the photographer to zoom in or zoom out on a subject. Lenses are often described by their focal length. For example, a lens may be called a 70-300mm lens. This indicates that the lens can zoom from 70mm to 300mm. Example of images taken with different focal lengths.

Aperture Ring: The aperture ring on a lens allows the photographer to control the aperture within the lens. These settings are marked on the lens using F-Stops. On automatic cameras the aperture can only be controlled through the camera body F-Stop settings.

Aperture: The aperture is an adjustable opening in the lens used to allow light onto the film or digital surface. The size of the aperture is measured by the F-Stop setting. The larger opening of the aperture results in less light needed to expose the image and less depth of field (less in focus). A smaller opening of the aperture results in more light needed to expose the image and more depth of field (more in focus).

Lens Mount: The lens mount is a metal area that has been machined into a particular shape to fit a specific camera body type. Each camera manufacturer uses a different lens mount design. The lens is attached to the camera at the lens mount ring by lining up a small dot on both the camera body and the lens. The lens is then gently rotated into place. The lens mount also contains contacts that will match up with contacts on the lens ring mount to allow the camera to control the lens.

Shutter: An opaque piece of metal or plastic inside your camera that prevents light from reaching the film or digital sensor. The shutter is opened, or released, by the shutter release button. The amount of time the shutter stays open is controlled by the shutter speed setting.

Shutter Speed Control: The shutter speed control is the point on your camera where you set the amount of time the shutter will remain open. On automatic cameras, this is generally accessed through a menu and displayed on a screen on the back of the camera. In manual cameras, the shutter speed is generally controlled and displayed on a knob on the top of the camera. The shutter speed is measured in fractions of a second but is generally shown as the denominator only. For example, 1/60 of a second is shown as 60.
Film Speed Control: The film speed control allows you to calibrate your camera's meter to your film speed so that you will get an accurate exposure reading. The film speed may be set electronically through a menu or via a knob/button on manual cameras. On manual cameras, the control is often integrated with a film speed indicator on the top of the camera. On automatic cameras, the control and film speed indicator are generally separate with the film speed being indicated on the electronic menu display on the back of the camera.

F-Stop Control: On automatic cameras, the F-Stop control is on the camera. For older manual cameras, the F-Stop is controlled on the lens. The F-Stop controls allow you to set the size of the aperture within the lens.

Film Compartment: In film cameras, there is a compartment in the back of the camera to hold the film. This compartment has a space for the film canister, sprockets to guide the film across the exposure area, a pressure plate to tighten the film, and a take up reel to wind the film. When the roll of film has been completely exposed, automatic cameras use a small motor to rewind the film. Manual cameras require the photographer to turn a small "rewind knob" to manually rewind the film into the canister. If the film is not rewound before the back compartment is opened, the film will be exposed to enough light to ruin the images.

Flash: Most cameras now include a built-in flash. Some are simple light bulbs built into the front of the camera. On SLR cameras, most built-in flashes pop-up out of a protective storage area on the top of the camera. External flashes can often be attached via the "hot shoe mount" or, in the case of manual cameras, an small connector port on the front of the camera that accepts a cable attached to a distant flash.

Hot Shoe Mount: The hot shoe mount is a point on the top of most SLR cameras where an external flash can be connected. It is called a "hot shoe" because it has electrical contact points and guide rails that fit over the bottom of the flash like a shoe.

Lens Ring Mount: On cameras that allow interchangeable lenses, there is a metal ring on the front of the camera where the lens will attach. This ring contains electrical contact points to connect the lens controls to the camera body. There is a small button or lever to the side of this mount called the "lens release button" that releases the lens from the body.
Lens: The lens is the part of the camera (or an attachment for the camera) that focuses light into the body and onto the film. The aperture is also contained within the lens.

Point and Shoot
Description
Point and shoot cameras mean just that, point the camera at something and trip the shutter. The camera does all the work for you. Unfortunately, the camera is rarely as smart as the photographer so the results can be iffy. Point and shoot cameras are often abbreviated as P&S. These cameras started out as a fixed lens that focused about 4 feet in front of the camera with a fixed aperture and shutter speed. It was basically a box with a shutter. Then the lab that developed the film did what it could to fix the exposure. Today's P&S cameras are much more sophisticated. While there are still some P&S film cameras, such as the disposable or one time use cameras, most P&S today are digital.

Features
• Metering systems, which calculate the amount of light entering the camera
• Variable shutter speed
• Variable aperture
• Zoom lenses
• Automatic focus
• Preset controls for various photographic situations such as:


Modes
• landscapes
• nighttime
• people
• close-up or macro

The biggest drawback to P&S cameras is that many do not have a through the lens (TTL) viewfinder. This means that what you see through your viewfinder may not be what you capture on film or digital media. P&S cameras are usually small and fit into a pocket or purse. They are best used for casual picture taking where capturing the memory is more important than creating a marketable image.

Popular P&S Cameras
• Kodak Easyshare series
• Canon Sureshot series
• Canon Powershot series
• Pentax Optio series
• Nikon Coolpix series

SLR and DSLR
Description
SLR stands for Single Lens Reflex and DSLR stands for Digital Single Lens Reflex and refers to how the light enters the camera. These are the cameras you see many professionals and serious amateurs lugging around. These cameras have a larger body than most P&S cameras and interchangeable lenses. While SLRs started out a fully manual, where the photographer had to control all features including focus, most of these cameras are capable of acting in a fully automatic mode just like a P&S. Many now allow the photographer the freedom to also take control of all functions or any combination of functions. These cameras allow for great control over the photography process and allow the photographer to take images not always possible with a P&S.

Features
SLRs and DSLRs allow for control over:
• shutter speed
• aperture
• film speed
• focus point
• magnification (through the use of various lenses)
• capability for add-on flashes
• remote releases
• additional battery packs

Popular DSLR Cameras
• Canon Digital Rebel
• Nikon D80

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