Rogue Safari focuses light the light from a DSLR"s pop-up flash to greatly increase the available flash (up to 8x over bare pop-up flash) power at extended distances. Safari is optimized for 100mm and longer telephoto lenses. Safari is designed to work with all crop-sensor (APS-C/DX) Canon and Nikon DSLRs. Nikon full-frame DSLRs (FX Sensor) like the D600 will have sub par Safari lens performance. Canon full-frame DSLRs like the 5D and 1D series do not have pop up flashes. Safari is not compatible with Sony or Pentax DSLRs. While the Rogue Safari pop-Up Flash Booster is compatible with the vast majority of modern DSLRs, some early model cameras will not accommodate the adapter.