21. Noise is a measure of the accuracy with which the incident light can be measured. 22. The simplest case is a single layer with thickness one-fourth the wavelength of incident light . 23. This property is used for frequency-selective optical filters, which can alter the color of incident light . 24. Therefore, spectral variations of incident light and environmental parameters are not taken into account under STC. 25. The incident light is assumed to be a plane wave, and effects of edges are neglected. 26. For unpolarized incident light , these are given by: 27. The resistance of a photoresistor decreases with increasing incident light intensity; in other words, it exhibits photoconductivity. 28. The Raman scattered light is emitted by the stimulation of the electric field of the incident light . 29. Higher plants sometimes employ strategies such as reorientation of leaf axes to minimize incident light striking the surface. 30. Parameters to measure are sediment accumulation, turbidity at the level of the filtering biota, and optionally incident light .