We have implemented a portable large-scale shadowgraph system for use in flow visualization relating to hydrogen safety. Previous large-scale shadowgraph and schlieren implementations have often been limited to background- oriented techniques which are subject to noise. The system built is based on a large-scale shadowgraph technique, developed by Settles, which allows for high-quality visualization. We have applied the shadowgraph system to complex phenomena and current issues in hydrogen safety including DDT in long channels, jet releases, and unconfined deflagrations. Shadowgrams taken are compared to a Z-schlieren system. This shadowgraph system allows analysis of these phenomena at longer length scales.