Hy, I want to make tiffs from a transient calculation (different timesteps). In the manual I saw how it works with windows-dumpster to get numbered pictures, but I did not get it to run with tiffs: the "percent-sign (%)" seems not to work. Can you help me ?

Use "%t" in the file name to get the files numbered with time steps. There are more hints on how to make movies in the thread entitled "Generating High Quality Movies", which you can find in the archives of this forum.