1. A video creation device comprising: a successive creator for successively and alternately creating, through imaging, a frame of a first type and a frame of a second type, wherein a frame of the second type has a shorter exposure than the frame of the first type; a difference determiner for determining whether or not a difference between frames of a determination pair exceeds a prescribed threshold, wherein the determination pair contains two frames of the first type next to each other in imaging timing, or the frame of the first type and the frame of the second type next to each other in imaging timing; a frame creator for creating, when the difference determiner determines that the difference exceeds the prescribed threshold, a frame of a third type between frames of a data pair in imaging timing based on the frames of the data pair, wherein the data pair contains two frames of the first type next to each other in imaging timing, or two frames of the second type next to each other in imaging timing; a synthesizer for creating high-dynamic-range frames by (i) successively synthesizing the successively and alternately created frame data of the first type and frame data of the second type when the difference determiner determines that the difference does not exceed the prescribed threshold, and (ii) successively synthesizing respective successive frame data of the third type and frame data of one of the first and second types when the difference determiner determines that the difference does exceed the prescribed threshold; a video creator for creating video from the high-dynamic-range frames synthesized by the synthesizer.