an imaging fluorometer is described comprising a source of electromagnetic radiation , optical components to direct the radiation , excitation and emission filters , and an imaging device . the fluorometer is used to obtain images of the fluorescence emitted by illuminated arrays of photosynthetic components , such as those found in leaves . these fluorescence images , in turn , are used to construct an image of the photosynthetic efficiency of the array . because efficiency in plants depends on the physiological state of the leaf , the fluorometer affords a method for the sensitive and rapid characterization of freeze damage , herbicide damage , and disease damage to plants . moreover , the fluorometer may be used in robotic applications , as well as for remote sensing from a location distant from the plant .