MIDI and AMBER from the user's point of view

This article introduces the two instruments MIDI and AMBER of the VLTI, for which observing proposals can be submitted. The instruments are described from a user's point of view without going very deep into their technical details. Emphasis is put on practical considerations that may be useful for the preparation of observations in the various stages including the first consideration of scientific ideas, the preparation of observing proposals, and the preparation of the actual observations after observing time has been granted. (c) 2007 Elsevier B.V. All rights reserved.