Resolving the time evolution of fast processes, measuring the time-of-flight of particles, and looking at time correlations in spatially resolved events are the main drivers for the development of imagers with the best possible time resolution. In the talk I will briefly review the fast imaging in general and then will discuss applications of a fast camera with 10 ns resolution to time resolved X-ray imaging and to imaging mass spectrometry. The camera, which is based on a silicon sensor and Timepix readout chip, successfully recorded the first data at several mass spectrometers and at NSLS-I.