Scotopic or night vision means that the human organ of vision works with very little light. In the scotopic vision, a person sees the world without colors, e.g. as in a black-and-white film. In the scotopic vision, the human eye can only distinguish the degree of brightness of elements in the environment. The ability to recognize image details also decreases. ¹⁾

Bokeh is the way a lens renders light in out-of-focus areas. It is a characteristic of the lens, depending on its design and aberrations. The word comes from Japanese and means “blur.” A particular lens is often said to have pleasant or unpleasant bokeh. ²⁾

A periscope is an optical instrument used to observe objects outside the field of view of the observer or covered by obstacles. The inventor of the prototype periscope - polemoscope was an astronomer from Gdansk - Johannes Hevelius. Hevelius constructed his instrument in the year 1637 and his description and technical drawings were included in the work “Selenography or Describing the Moon”. ³⁾

A green ray or green flash is a rare phenomenon occurring in the atmosphere during sunset and sunrise. Just above the setting or rising Sun or just after it has hidden behind the horizon, a small usually green area in the sky is visible for a few seconds. ⁴⁾

A rainbow is an optical and meteorological phenomenon occurring in the form of a characteristic multicolored arc resulting from the splitting of visible light. Light splitting in this case is a result of the phenomenon of dispersion (as in a prism), resulting from differences in the angle of refraction of light of different wavelengths when passing from air to water and from water to air. Diffraction, on the other hand, is the splitting of light as it passes through a slit, and does not occur here. ⁵⁾