In this paper, we provide a detailed description of the main features of the upgraded version of a spectrophotometric apparatus developed by our team since 2014 [Opt. Express 23, 26863 (2015)]), and whose improved performance allows the characterization over the visible and near infrared part of the spectrum of the transmittance of complex interference filters with high spectral resolution (approximately one tenth of a nanometer) and an extremely wide dynamic range (thirteen decades).