The ricoh gf 1 flashgun is a high performance external flashgun for the ricoh gxr and gr digital iii cameras it offers full ttl metering for accurate exposure bounce flash for indirect lighting and a built in wide angle diffuser that provides flash coverage to an equivalent focal length of 18mm without the diffuser in place the zoom flash head provides coverage for focal lengths between 24mm and 105mm with a maximum guide number at 105mm of 33 metres at iso 100