This application note reviews the options of fast-acquisition TCSPC FLIM. We describe the parameters which limit the acquisition speed, both in the sample and in the recording system. We show that a standard bh FLIM system is able to record and display FLIM images at a rate much higher rate than commonly believed. We describe how faster acquisition times and faster image rates are obtained in the bh FASTAC FLIM system. Moreover, we show how fast dynamic changes in the fluorescence behaviour of a sample can be recorded under conditions where the sample does not deliver the count rate required for fast-acquisition FLIM.