Bit Depth

Electronic imaging systems must digitize the analog intensity signals that are generated by each pixel. The number of discrete levels that the signal range of that pixel is broken into is called the Bit Depth. This is expressed as 2^N levels. For example, 2⁸ levels of bit depth correspond to 256 (2⁸=256). Such a system would be considered to have an 8 bit depth. A 12 bit system would have 2¹² = 4,096 discrete levels that the intensity range of each pixel is divided into. While the total range of the pixel is the same in either case, a 12 bit system will show finer levels than an 8 bit system, since the total range is divided into smaller pieces.