An explicit expression is given for the correlation function of blinking systems, i.e., systems exhibiting light and dark periods in their fluorescence. We show through the example of terrylene in a crystalline host that it is possible to determine by means of this explicit expression photophysical parameters, like Einstein coefficients and the mean light and dark periods. In addition we obtain further parameters like the frequency of the various intensity periods and the probability density of photons scattered off the host crystal. It turns out that this approach is simpler and allows greater accuracy than previous procedures. (C) 2003 American Institute of Physics.