Online Tutorials: Sensors
With today's technology, the sensor is what records the photograph taken with the camera. For those who still shoot with film, this is the direct equivalent.
Sensors have improved drastically over the last 15 years with regard to sensitivity and clarity. Modern sensors have ISO ratings up to 102400, which is extremely sensitive compared to the maximum from the year 2005 of 1600, for example.
The pixel density of these sensors has also improved. In the 1990s, pixel densities were less than 2 megapixels, where today's sensors for D-SLRs range up to 50 megapixels.
Digital cameras can now also be found on a range of devices including mobile phones, games consoles, compact cameras, compact system cameras and SLRs and this list is certain to get longer. Each camera type has its advantages and disadvantages. Phone cameras are always available but have very small sensors and cheaper optics, limiting thier capabilities as a camera. Compact cameras are lightweight and can produce many respectable images. SLR cameras have large sensors which assist in gathering light and will do so more efficiently, but they are often more bulky and heavy to carry around. 4/3, or compact system cameras, combine some of the advantages of an SLR (interchangeable lenses, larger sensors) with the more convenient size and weight of a compact camera.
One thing to note about all of these types of camera is their sensor size. A larger sensor can have more pixels on it, increasing the capabilities of the sensor. Alternatively, the pixels can be larger and not so close together, thus increasing the light sensitivity of the sensor and increasing the ISO capabilities of the camera.
The illustration shows the comparative sizes of a variety of camera sensors from a variety of readily available camera types. Every year, higher resolution cameras are put on sale, with even higher pixel densities and higher ISO ratings. As technology moves forward, we gain from these improved methods and technologies.