Imaging mode

Imaging with occulting bars

As well as direct imaging over the entire field of view of FORS2, it is possible to use the movable slitlets of the MOS in order to occult any unwanted regions of the field, for instance when a bright star is present in the field that will cause the CCD to saturate even with the shortest exposure times. (In this case, fast acquisition in not possible and a mask must be designed in FIMS)


Here is the list of available filters.Observers who wish to use their own filters must comply with the non-standard filter policy.

High accuracy photometry

Recently, a lot of work has been done by the IOT and friends to investigate the limiting absolute photometric accuracy of FORS observations, with the objective of offering a recipe for Service Mode users to follow in order to ensure a specific level. Whilst work on the implementation of this recipe is ongoing, there are a number of publications based on the background work which might be of interest to users. They can be downloaded from the links below