The main ESO Archive interface is intended to aid general queries, especially to astronomers with no previous experience with ESO telescopes and instruments.

The instrument specific pages will help in finding observations which are either specific to the observing strategy, like stacks in the infrared, or to the detector or instrument setups. These pages should be used when you are searching for specific data (e.g. infrared spectra) for a given object or when you are searching individual observation programs.