Data Reduction Frequently Asked Questions
My rectified and wavelength calibrated data show regions of negative flux adjacent to bright spectra and the 1D spectra look quite bad. How can I fix that?
The fringe correction can sometimes produce such effects for dithered data. You can switch it off by setting the parameter fringing to FALSE.
The figure shows this effect for VIMOS.2013-06-18T01:59:53.173 - the left part shows the result with fringe correction, the right one shows the result obtained without fringe correction.