Disturbance free fragmentation and flow in sublevel caving (SLC) are desirable as they could lead to an increase in ore recovery and a decrease in waste rock loading and nitrates leakage. This requires a reasonable understanding of the actual rock breakage in semi-confined ring blasting situations, where both the blasted geometry and the breakage itself are hidden. Sometimes there is a chance to inspect the actual conditions, such as in the opening of a new drawpoint and in hang-ups in which cavities exist. For these situations a lightweight mobile camera crane has been constructed for use in the LKAB Kiruna mine. A 3D photogrammetry system has been constructed, which enables the reconstruction of the ring front/cavity as a geo-referenced mesh model with color information. It is remotely operated from a safe distance behind in the drift. The paper first reviews the current drill and blast practice. Then it presents the design, construction and application of the 3D image acquisition system. A case study shows the measurement application and also the evaluation possibilities. So far the system promises to be a valuable tool in increasing the understanding of SLC breakage and flow.