A Camera is an optical instrument that captures or records a visual image that can be stored directly and transmitted to another location.Camera is very similar to the functioning of Human Eye.
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 word Photography has Greek roots, ‘Photo’ + ‘Graphe’, which roughly means writing or drawing by light. Camera is nothing but a tool that enables writing with the help of light.
The word Camera originally is derived from the Greek word ‘Kamara’, meaning a dark room. It is a shortened version of the Latin name ‘Camera Obscura’, which was a light proof tent (a dark chamber), allowing light to enter through an opening fitted with a lens. The lens was used to collect and converge light to a point, just like it happens in the case of a magnifying mirror.
At a basic level, cameras consist of sealed boxes (the camera body), with a small hole (the aperture) that allows light through to capture an image on a light-sensitive surface (usually a digital sensor or photographic film).
What is A Digital Camera ?
A digital camera utilizes the same optical principles as a film camera, aided with a small photosensitive chip that has replaced the film. So while the chip converts the light energy into electric signals, another chip, or memory card stores these signals in form of digital data.
Major Parts of Digital Camera-
In Digital Camera there are four major parts-Lens, Image sensor , Image Processing Unit and Recording media.
Lens-
Designed to collect light reflecting off the subject and transmit it to a CCD (Charge-Coupled Device) or similar type of image sensor.A lens is a finely polished glass, curved on both sides, used to allow light to enter the camera and focus the image on the sensor. A photography lens is usually an assembly of lenses that are adjusted in order to achieve the desired image. Better the lens of a camera, better the photographs being capture.
Image Sensor –
An image sensor is an electronic device that converts an optical image (photons) into an electronic signal that can be interpreted by the device. So image sensor electronically captures an image.
CCD –
CCD is a light-sensitive integrated circuit that captures images by converting photons to electrons. A CCD sensor breaks the image elements into pixels. Each pixel is converted into an electrical charge whose intensity is related to the intensity of light captured by that pixel.
Image Processing Unit-
An image processing unit (IPU), also known as an image processing engine, image processor, or image signal processor (ISP), is a type of media processor or specialized digital signal processor (DSP) used for image processing, in digital cameras or other devices. Converts the electronically captures image into digital data and performs various types of image processing such as Bayer transformation, Demosaicing, Noise reduction and Image sharpening.
Recording Media-
Records digital data to a memory card or other type of digital recording media for saving the captured images to. Examples of recording media are Compact Flash (CF) and Secure Digital (SD) cards. SD cards are the most predominant format, due to their small size.