Monochrome photography - online puzzles

Monochrome photography is photography where each position on an image can record and show a different amount of light, but not a different hue. It includes all forms of black -and- white photography, which produce images containing tones of neutral grey ranging from black to white. Other hues besides grey, such as sepia, cyan or brown can also be used in monochrome photography. In the contemporary world, monochrome photography is mostly used for artistic purposes and certain technical imaging applications, rather than for visually accurate reproduction of scenes.