Powder diffraction covers a variety of applications ranging from high resolution structure determination to time-resolved experiments. This wide range can be covered if the properties of synchrotron radiation, especially the continuous spectrum and the high collimation, are properly taken advantage of. The latter property favours parallel beam geometry. The instrumental function for such a setup is aberration-free and can be derived using only the angular characteristics of its optical components, namely the divergence of the incoming beam and the reflection or transmission curves of the optical elements. The continuous spectrum allows either anomalous dispersion experiments or the use of a broad energy band for experiments on a short time ...