What is a Pixel?

A pixel, also called an element in PDAs, is an individual semiconductor in a larger array of many semiconductors used in electronic detectors such as CCDs and PDAs. When using detectors for 2D imaging, these semiconductors correspond directly to the pixels in the digital image, hence the name. Pixels influence the resolution of a spectrometer because a pixel is the smallest spatial area that can be resolved on the detector. The grating might be able to disperse 500 nm and 501 nm, but if those wavelengths hit the same pixel, the detector can’t tell the difference between them.