Kryssfilter

Kryssfilter is a term often encountered in the context of photography and optics, particularly in relation to polarizing filters. A kryssfilter, which translates to "cross filter" in English, is essentially two polarizing filters stacked on top of each other. When one polarizing filter is rotated relative to another, the amount of light that passes through can be adjusted, from maximum transmission to complete blockage.

In photography, this effect can be used to control reflections or enhance color saturation. By precisely aligning the polarization axes of the two filters, photographers can achieve specific visual effects. For instance, rotating the filters can dramatically alter the appearance of reflections on water or glass, or deepen the blue of the sky. The precise amount of light reduction depends on the angle between the two polarizing elements.

The term kryssfilter is most commonly used in Scandinavian languages and refers to this specific construction of stacked polarizers. It's a tool that allows for fine-tuned control over light polarization, offering creative possibilities for image manipulation without digital post-processing. While the underlying principle is simple polarization, the combination of two filters in a kryssfilter configuration provides a wider range of controllable effects compared to a single polarizing filter.