Digital Cameras: What Is the Tonal Range of an Image?
In digital cameras, tonal range refers to the total number of tones possible in the image. Tone is the effect that light has on color. In black and white terms, tone is shades of gray. Since images in digital cameras are created by sensors, tonal range is affected by dynamic range. To visualize what tonal range looks like, think of gradient images.
Understanding Tonal Range
Because gray's tonal range is black and white, we will use it as an example of what tonal range looks like. With high tonal range, gray would appear white at one end of the spectrum and black on the other. In between will be various shades of gray that go from light to dark. In low tonal range, the spectrum appears to be closer to a solid color than gradient. It would go from slightly light gray to slightly dark gray.
So why is tonal range so important? Because it adds more shades of colors to the image, which creates more detail. The human eye observes light in various shades and the camera should too. Unless you're going for a simple look, you should always try to achieve high tonal range in your photos to give them high quality.