TY - JOUR A1 - Feito Boirac, Alvaro Felipe A1 - Lundeen, Jeff S. A1 - Coldenstrodt-Ronge, Hendrik A1 - Eisert, Jens A1 - Plenio, Martin B. A1 - Walmsley, Ian A. T1 - Measuring measurement : theory and practice N2 - Recent efforts have applied quantum tomography techniques to the calibration and characterization of complex quantum detectors using minimal assumptions. In this work, we provide detail and insight concerning the formalism, the experimental and theoretical challenges and the scope of these tomographical tools. Our focus is on the detection of photons with avalanche photodiodes and photon-number resolving detectors and our approach is to fully characterize the quantum operators describing these detectors with a minimal set of well-specified assumptions. The formalism is completely general and can be applied to a wide range of detectors. Y1 - 2009 UR - http://iopscience.iop.org/1367-2630 U6 - https://doi.org/10.1088/1367-2630/11/9/093038 SN - 1367-2630 ER -