A camera is an optical device that is used to capture an image. Normal usage cameras can capture 2D images but some new technology cameras can capture 3D images as well. Basically, the camera consists of sealed boxes and a small hole that allows light to pass through and fall on a light-sensitive surface such as photographic film or digital sensors. Cameras have different techniques to control the falls of light on a sensitive surface. Lenses are used to focus entering light and the aperture is used to widen or narrow. A shutter is used to open or close the entrance of light.
The lens is used to focus on the subject, it basically captures the light reflected from the object and focuses on the sensor. The image quality depends on the manufacturing of the lens. A technological revolution has too much contributed and modernized lens design such as reading glasses and microscopes.
Camera lenses have a wide range of focal lengths, such as extreme wide angle, standard, and medium telephoto. Focal length is the most important factor to consider when choosing a camera lens. This is the distance from the lens to the sensor, and it determines the field of view. A longer focal length gives you a narrower field of view, while a shorter focal length gives you a wider field of view.
The opening from which the light comes in, light entering space that can adjust by overlapping plates called the aperture ring. It is generally located in the lens, this opening can be widened or narrowed to control the amount of light that falls on the surface of the sensor. The radius of the aperture can be increased or decreased manually by rotating the lens, or in automatic using an internal light meter.
The expansion and contraction of the aperture is called f-stops. A large amount of light is passed through if the f-stop is smaller. Typically, f-stops range from f/1.4 to f/32 in standard increments: 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, and 32.
The shutter is used to control the amount of light entering in camera. The shutter controls the time duration when the light-sensitive surface is exposed to light. When the shutter is open the light-sensitive surface is exposed and then closed. The duration in which the shutter is open and closed is called shutter speed. Normally its speed range is one second to 1/1,000 seconds
There are two types of mechanical shutters: one is leaf-type and another one is the focal-plane shutter.
The leaf-type uses a circular iris diaphragm that is just behind the lens and it is open and closes quickly.
In the focal-plane shutter type, the metal blades move vertically.
The objects within a certain range distance from the camera have clear image quality. The process of adjusting the range to get clear and detailed image quality is known as changing the camera’s focus. We basically change the distance between the lenses and the camera sensor to get a better result by manually or automatically using electrical motors.
In modern technology cameras, the amount of entering light through the shutter is measured by using a but-in light meter. These readings are taken using light-sensitive semiconductors called Taken through-lens metering (TTL). These readings are used to calculate aperture settings and exposure times.
Types Of Cameras
Single-lens reflex (SLR) camera
SLR stands for Single-lens reflex camera, this camera is basically used as a mirror and prism system that allows the user to view through the lens what exactly will be captured. In twin-lens reflex cameras, the viewed image is different from the final image. When the shutter button is pressed of SLRs, the mirror moves out from the light path and allows it to pass through the light receptor image to be captured.
A plate camera is one that has a light-sensitive surface such as glass coated with light-sensitive chemicals or single pieces of film, each one is capable of taking one photo. The early-age camera was loaded in the dark due to light-sensitive material film. After some time the cameras are loaded using a plate holder, a box containing the plate which could be fitted inside the camera. This is more helpful because we can load the light-sensitive film even away from the darkroom.
Medium-format cameras have a medium film size compared to smaller 35mm and large-format cameras. Normally these format cameras use 120 or 220-roll film. The common sizes are 6×7 cm, 6×4.5 cm, and 6×6 cm. But nowadays these cameras are obscure due to the modern age of digital cameras.
Twin-lens reflex camera
TLR stands for Twin-lens reflex camera, this type of camera has two nearly the same lenses one is to form images and one is for the viewfinder. The viewing lens projects an image onto the screen which is visible from above. The main advantage of TLRs was that they can easily be focused on the viewing screen and record the same as viewed on the view screen. Most TLRs used 120 or 220 films, some other TLRs used the smaller 127 films.
In the large-format camera, the large format refers to any format having a size of 9 cm × 12 cm or more larger size. The larger format is much larger than the medium format. The large-format camera means that the frame of the camera measures a minimum of 4×5 inches or larger frame.
Compact Cameras Types
An instant camera is a camera that has built-in image development mechanisms. This instant camera mechanism allows users to access images a second after your capture. It includes all the chemicals you need to create an image, when you take a snap the special rollers draw the image using chemicals. Instant cameras are useful in an urgent situation and it is popular because of on spot giving results.
Subminiature cameras were first produced in the nineteenth century and these cameras use 35mm film. A subminiature camera is a very small type of camera than the miniature camera. The 35 mm cine film was originally called a miniature camera. A camera that uses less or smaller film than 35mm is called a sub-miniature camera, and the smallest of these are known as referred to as ultra-miniature.
It is also another type of camera that folds into a compact and small package. The lens and shutter are attracted to a board and fold inside the battery of the camera. It provides the correct focal distance from the camera sensor when it is fully unfolded. The advantage and popularity gained by this camera is due to its physical size. These were popular early 1930s.
A Rangefinder camera is having a range-finding mechanism that allows users to measure the distance between the subject and the camera, it allows them to take sharp and focused images. This camera can make quick exposures without losing focusing the subject. The early design had a separate viewfinder and rangefinder but later on, modern designs have rangefinders coupled to the focusing mechanism.
Motion picture cameras
A motion picture camera is a type of camera that takes images rapidly, either on a light-sensitive film or on the sensor. This camera is capable of taking several images at a time which combine together to form a video output.
As the name of this camera tells that the camera has the shape of a box. It is made of plastic or cardboard having a lens on one side and light-sensitive film on another side. This is a budget-level camera that has originally small reflex viewfinder on top of the camera and had no focusing controls or aperture. These cameras were very popular during the 19th century. Its performance was good in daylight and in a dark place, but its image quality suffers a lot.
Professional video camera
A camcorder is one that can record video and sound at the same time, it can record data on a digital disc and memory card and it allows to transfer of data to other storage mediums. Its image quality does not match full-size professional equipment. Initially, the camcorders were analog but now they have been replaced by digital camcorders, digital camcorders have much better image quality.
It is a type of camera that captures image digitally and stores them on the computer, display them on the screen, and is a lot faster than a normal camera. The digital camera captures images when light falls on the light-sensitive sensor. Digital cameras are mostly used in now a day even a smartphone does have a decent digital camera.