ah right on.. I think most likely the tree is causing this effect.
That said, if the tree is giving you the creeps maybe try some photos in the hollow part? Many here in Okinawa believe in haunted trees. I have seen locals that won't even go near certain trees.Granted, traditionally the island has had animistic beliefs which attribute spirits to many things but I find this an easy belief to follow as when we think of things that have been around for a long time trees are certainly up there on the list