  Individual-qubit readout is a key ingredient for quantum simulation and
quantum computation. Furthermore, this readout must take place in real-time to
enable the application of quantum error-correction protocols. In this paper the
capability of an EMCCD camera with a real-time processing capable output is
demonstrated to determine the quantum state of a single $^9$Be$^+$ ion and the
required timing sequences are explored. The results are comparable to a PMT
based detection. Experiments on the individual detection of $^9$Be$^+$ qubit
states undergoing coherent excitation are reported. Sources of error and the
amount of crosstalk in the detection system are discussed. Error rates due to
known problems in the state preparation and measurement processes were
determined to be approximately 0.5 %.
