The dynamic range of a CCD camera (DR) is the maximum signal (which is directly related to the full-well capacity (FWC)) divided by the camera noise (CN), the combination of the dark and readout noises: DR = FWC/CN. The higher the dynamic range the more reliable is the quantification of differences between the dimmest and the brightest intensities of an image taken. The dynamic range is sometimes measured in decibels (DR = 20 x log(FWC/CN) or approximated in bits.

The dynamic range of acquired image data is maximum intensity divided by total noise. At high light levels it is practically limited by the signal noise, that is, the square root of the maximum signal of the image (prior to digitization). An example: The maximum signal is 18,000 electrons from which a signal noise of about 134 results. With a camera noise of, say, 5 electrons the total noise is 139 electrons and the dynamic range of the data is 18,000:139 = 129. After digitization with a conversion factor of 5 the maximum count is 3600 and the noise 28.

Note: Some camera manufacturers call the signal digitization "dynamic range". However, this is rather the maximum possible intensity range or bit depth of the digitized images.

The intrascene dynamic range of an image (intensity range, difference between brightest and dimmest pixel) is determined by camera gain, exposure time, sample staining, microscope settings, background intensity, display palette and so on and can be represented by the intensity histogram.