Reproducing the full range of tones or brightness values seen by the human eye is one of the most fundamental challenges in photography. Capture, display and print technologies are all limited when compared to the ability of the human eye to see a wide dynamic range. They’re all advancing. As they advance, our methods for addressing this fundamental challenge advance with them.

Prior to the 21st century, black-and-white photographers developed a heightened sensitivity to the direction and intensity of light, a given relationship between highlights and shadows, largely discounting the appearance of hue and saturation unless able and willing to use color filtration during exposure. These perceptual skills are all very important for 21st century digital black-and-white photographers. But, today, because you can make any hue light or dark, globally or locally, and you can make more dramatic changes to more saturated hues, hue and saturation need to be factored in rather than factored out.

Not all white lights are the same. Differences in white light are commonly described by their color temperatures (rated in Kelvin). The lower the number, the warmer the light; the higher the number, the cooler the light. Light temperature has a significant effect on exposure, calibration, printing and display.

The ability to reproduce detail is one of the essential characteristics that defines the photographic medium. While there are many similarities between the camera eye and the human eye, there are also significant differences between the two. One of the most significant differences is that the camera eye can achieve a much greater area of focus than the human eye can at one time. This has never been more true than today.