Device for visual observation of the chlorophyll fluorescence in the environment

摘要

A device for the visual observation of chlorophyll fluorescence in the environment comprises an optical filter which is not only transparent in the spectral range in which chlorophyll fluorescence occurs, but also has an additional transparency band lying in the 400 to 525 nm range. The purpose of this additional band is to enable the human eye to operate in its ''brightness sensitivity'' range attaining longer wavelengths. The eye thus becomes more sensitive to chlorophyll fluorescence. The suitable choice of the height and length of the maximum of this additional band brings about a ''white compensation'' in such a way that the human eye sees the objects observed which emit no chlorophyll fluorescence substantially in natural colours, while the chlorophyll-containing objects appear red.