Back to photostream

Tree Burl Bear Claw Ilusion (Convex)

This is fascinating....well, at least to me. This is a burl on a tree trunk. The next photo on my stream is the exact same image. I have done nothing to the second photo but turn the first one upside down. But as soon as I did so, the "convex" burl, (which looks a lot like a bear paw) suddenly appears to look concave. Even the individual "claws" look concave, like a track made on soft ground. I assume it appears this way to others and is not due to brain damage on my part. Any theories from you Flickr folks on why this is occurring? I don't remember ever seeing this phenomenon before.

745 views
14 faves
1 comment
Uploaded on August 21, 2018
Taken on August 14, 2018