Detonation velocity (VOD) is one of the most important parameters describing the detonation process of a particular explosive. This article summarizes some peculiarities that we have come across when building and testing our new passive optical VOD meter - OPTIMEX. The advantages of using multiple probes with independent signal recording is discussed. The practical issues related to an explosive's translucency are solved. Finally, a new method for detonation velocity data evaluation is proposed and demonstrated.