Monochromatic filtering of VIS light

Screening in monochromatic light is based on the rules for color separation and helps to identify restoration retouches, to define their extention, make better visible artist‘s signatures or other details.

The human eye hardly distinguishes between near hues of the spectral scale and often perceivs as the same colors of different composition. For example, faded blue and green are almost indistinguishable from each other, but illuminating them with light at whose source is set a blue color filter, the blue object will appear much brighter than the green as it reflects more blue light than the green.

For monitoring in monochromatic light usually is used a standard filter or combination of such (for to render the acquisitions comparable), selected after the principle of complementary colors: when the details are, for example, in greenish-blue coloration a red filter should be used, for blue – an yellow, and so on. Given this rigorous dependence and its influence on the results, the use of the term “false color”doesn’t seem opportune in a scientific context.

When working with filters, visual observation and photography must be performed always under direct light. It should be also remembered that, since the human eye and the photographic emulsion react differently to different color relationships, photographic effect may differ from the visually observed, and the contrast can also be different.