while using my drone at buckeye park in lepsic Ohio 7-13-19 hovering at 386 ft agl 128ft northeast from st16s and in park boundry. I was focusing my h520 to watch the rail junction of ns and csx. While doing so I heard a sound that did not sound right and right in front of me under 50ft agl came a dji mavic unit. did a quick glance back to my h520 to make sure it was holding in place. which is was. I step to the side so it would not fly right over me. It's flight path away from me confirmed it was a not a line of sight type flight. not even sure the dji was registered no markings were visuable from the side front or back or bottom. hopefully it was on the top of the unit but that was not visuable to me.