APS or Active Pixel Sensor is a semiconductor detector for measuring light manufactured with CMOS technology and therefore often referred to as CMOS sensor. Using the CMOS technology, it becomes possible to integrate other functions in the APS sensor chip, such as the exposure control, contrast correction or the analog-digital conversion. In the article, Image sensor of Digital Camera, we discussed about both CMOS and CCD used in Digital Photography.
Brief Technical points about APS or Active Pixel Sensor
There was Passive Pixel Sensor – they were passive as they lack their own amplifiers, they were being investigated as a solid-state alternative to vacuum-tube imaging devices. APS or Active Pixel Sensor is more speedy. APS or Active Pixel Sensor consume less power that the other technology – CCDs. Manufacturers deployed APS or Active Pixel Sensor in many consumer products not only in Digital Cameras. So the nomenclature of APS or CMOS has some history. Without going to in depth details, in simple sentence - APS or Active Pixel Sensor is used as an alternative to CCD image sensors.
Major usages of APS or Active Pixel Sensor
APS or Active Pixel Sensor is widely used in Photography, in modern Digital Cameras. Other usages are in digital radiography or digital X-Ray that is widely used now for correct magnification ratio. Traditional XRay has an arbitrary magnification ratio with over +/- 10% error in calculation.
Other usages of APS or Active Pixel Sensor are in ultra high speed image processing, security cameras and in military, airlines.
Most manufacturers are quite interested in APS or Active Pixel Sensor technology because the process of manufacturing is easy, they can scaled down to a small unit, does not come huge battery and the manufacturing unit can operate longer increasing return of investment in all aspects.
The consumers definitely are benefited as the price comes down.
Problem of APS or Active Pixel Sensor in Digital Photography
The biggest problem with APS or Active Pixel Sensor in digital cameras are sensitivity differences from unit to unit as well as between pixels, added image artifacts etc. Furthermore the Size of APS is some what not maintained to the standards by the manufactures.