I just got hold of a older Vivitar 16A flash. I say older, because most of the 16A's I see on the internet look slightly different than the one I've got. It has the hotshoe mount, and also has the remote cable. It was originally used on an old Minolta camera. Does anyone know if this flash would work with my newer Pentax *ist D? I've heard there can be voltage issues with older flashes, so I don't want to just put it on and try it.