u201c autoconfig frap u201d in the embodiment of fig7 the system allows the control of the pre modification phase modification phase post modification phase and analysis phase as described in relation to fig5 the parameters used at each stage are those that permit an exploration of the possible parameters of the sample so as to quickly and efficiently determine the hardware settings laser power modification duration etc by an iterative process and these settings are passed to knowledge base mentioned in connection with fig3 with the appropriate filter sets the system may be able to image during the modification phase for example during a bleach process to monitor the parameters of the modification in a further embodiment the sample contains one or more photo switchable labels so that the activating light beam is able to activate quench or switch the label as described above in order to observe the labelled component over short fast moving components medium or long time scales rare events or configurations the labels may comprise a naturally occurring fluorescent molecule such as nadh a calcium probe such as u201c fura u201d and or an antibody tagged with a fluorescent molecule and bound to a selected species the labels may comprise a pair of fluorescent molecules with overlapping emission excitation spectra of the types used in fluorescence resonant energy transfer u201c fret u201d and the activating light beam may be set to photo bleach the acceptor molecule in a region of the sample.