FinePix IS Pro filters are required to photograph in IR or UV wavelengths. Infrared filters are readily available at low cost from many sources, but ultraviolet filters – and suitable lenses – can be expensive. Photography in infrared and ultraviolet poses its own special challenges regarding exposure and – above all – focusing a SLR camera. By definition, these forms of light are invisible to the human eye. The IS Pro includes a Live View mode that relays what the sensor sees as live video to the LCD screen (and, optionally, via USB to a computer running appropriate software). Some lenses have separate
Photoacoustic effect added steady light does not produce any photoacoustic effect by itself, but changes the photoacoustic response due to the modulated/pulsed probing light. The resulting signal serves as a reference to all other measurements in absence of the background light. The photothermal part of the reference signal is maximal, since at photosynthetic saturation no energy is stored. At the same time the contribution of the other mechanisms tends to zero at saturation. Thus the reference signal is proportional to the total absorbed light energy. In order to separate and define the photobaric and photothermal contributions in spongy samples (leaves, lichens) one