22/05/13The Dynamic Range of a camera is typically defined as the camera’s ability to detect both bright and dim signals in the same image. In imaging applications involving the precise measurement of intensity of light, dynamic range can also be defined as the number of discrete intensity measurement steps that a camera can deliver, though the mathematical definition is the same.
Figure 1 visualizes the relationship between full well capacity and dynamic range. Figuer 1A : The low full well capacity makes the image lost bright signals information. Figuer 1B : The high full well capacity make the image get full information from weak to bright signals.
A camera with high dynamic range will be able to detect strong signals without saturation, while weak signals are not lost above the camera’s noise floor. Dynamic range is most commonly quoted as a ratio in decibels (dB), referring to the ratio between the brightest possible signal detectable, represented by the full well capacity, versus the camera’s noise floor, given by the camera read noise. Both of these quantities are measured in electrons, and the formula to convert to a ratio in decibels is:
