Machines and methods measure an unknown characteristic of an optical signal incident upon a detector characterized by one or more dynamic response parameters. One method receives an output signal from the detector and compares that output signal and a computationally determined response of the detector to a known optical signal incident upon the detector. The response is based on said one or more dynamic parameters. The method determines the unknown characteristic based on the comparison of the output signal and the computationally determined response of the detector. Another method receives an output signal from an optical detector detecting one or more optical signals, accesses a predetermined characteristic curve of detector response, compares the output signal from the detector to the predetermined characteristic curve of detector response, and calculates at least one unknown characteristic of one or more optical signals based on results of the comparing step.