Monday, 24 February 2014

When stuff just disappears

Dark crowAnyway, I was looking out of a window at the outside world when I noticed something disquieting. A familiar post looked rather shorter than normal, which should be impossible. I got some binoculars for a closer look but even with them, the top appeared to be entirely missing!

Later in the day I looked again. Now the post appeared whole and normal, even without binoculars. So how had I been completely unable, even with the aid of binoculars, to see the top of the post, no more than about 7m away and with nothing in between, earlier? It defied belief! How can part of a post just go missing in broad daylight and then reappear? Indeed, I had trouble believing what I wasn't seeing at the time. The top of the post actually appeared to be missing!

Not so dark crowIt was one of those contrasty days. I suspect only a photographer would ever say that. After a while, photographers start to think about the the world the way their camera sees it, which can be markedly different to what is seen with the naked eye. A photo would definitely have shown the top of the post as having a dark shadow over it. No details would have been visible in the shadow (like the big black blob in the photo above right). However, the naked eye has a bigger dynamic range than a digital camera sensor. That means it can distinguish more shades of grey between black and white and see details in shadows where a photo of the same scene shows none. As expected, I COULD see some details in the shadow, particularly with the binoculars, but the top of the post was simply not there!

The ability of shadows to alter or even completely hide important details of a scene can help to explain some paranormal reports where objects apparently disappear or appear from nowhere. We tend to think of bright sunshine as being excellent viewing conditions but, particularly when the sun is low, this not necessarily true. The top of the post became visible again in overcast conditions!

The lower photo is the original of the one above which has been artificially darkened to obscure the identity of the crow. Details often go missing in shadows in photos. This can explain apparently how, in some anomalous photos, things can appear quite different to what the witness remembers of the scene. It's not paranormal, just lack of dynamic range.

PS: I found this excellent post in a blog recently. I like the video which looks like moving shadow ghosts to me.

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