In this page, you will find all the manuals needed to prepare and analyse your observations with FORS2. Please be sure to download the manual corresponding to the period in which the observations will take place.
All the manuals are in Adobe's Acrobat format.
- FORS2 User Manuals
All the information about the instrument itself, its modes and their characteristics is provided in the FORS2 User Manual (UM):
- valid for observations in P106 (ending April 2021), P107 (Starting April 2021) and for the CfP for period P108 (from October 2021): P106.1. (No changes between P106.1 and P108 UM versions.)
- FORS2 last User Manual with reference to HIT modes: Period 101.1
- FORS2 Template User Manual
Detailed information on the acquisition, observation, and calibration templates:
- FORS2 FIMS User Manual
Detailed information on the Instrumental Mask Simulator software tool to prepare precise target acquisitions at Phase 2:
- FORS1+2 data reduction Pipeline
The various pipeline recipes to reduce FORS data are available here. Documentation on the FORS2 pipeline and its use - in the form of cookbooks - can be found here:
- REFLEX Tutorial
Tutorial reflex workflows for FORS2 can be found on the VLT pipeline page here.
- Data reduction frequently asked questions
A list of Frequently Asked Questions on data reduction is also available.
- FORS2 Absolute Photometry Project
Detailed information on the FORS Absolute Photometry (FAP) project, whose goal is to produce a 3% absolute photometric accuracy,
if nights are photometric (see Freudling et al., 2006).
Nightly zeropoints and extinction coefficients are available at
and the description of the table entries and definitions can be found at
Due to the method used, the nightly zeropoints become available with a delay of about 4 weeks.
- Historical FORS1+FORS2 User Manual
The Period 82 version of the User Manual contains information on FORS1 and FORS2 prior to the merger of the two instruments in 2008.