Tuesday, 25 June 2013

A white transparent ghost?

Blury bushThe two men stopped, politely, while I took my photos so as not to intrude into the shots. After I'd finished they asked me what I was photographing. It was a reasonable question as, to the casual observer, there was nothing remarkable about the bushes. Indeed, as you can see in the resulting photo (right), there isn't much going on in this photo, though you may notice some white blurred objects. And those were, indeed, my subjects.

Had I taken this photo without noticing the blurry objects, which would have been very easy, I might have been puzzled when I later examined the photos. The photo could easily have been reported as paranormal. Maybe even a photo of a ghost, perhaps! Ghosts are often seen as white, transparent and fuzzy in TV ghost stories. In real life cases, by contrast, ghosts are usually reported as looking like perfectly solid normal-looking human figures. If anyone knows of any reports of fuzy transparent ghosts (not involving photos), I'd love to hear about them.

Blurry bush 2Anyway, I took a second set of photos of the same scene. This time I set the focus manually so I could get the blurry white objects clearer. As you can see (right) I didn't entirely succeed as they were constantly flying about. They are midges. The passers-by seemed impressed that I was photographing such a subject, when I told them, though I'm not sure why.

In this second photo you can see that many of the midges have become flying rods. Others appear more insect-like. Some insects are flying horizontal to the camera, so appearing a linear rods. Others are flying towards, or away from, the camera and so look more like ordinary insects.

But why are the insects all white when, in fact, midges are nearer to black in colour? It's because they are overexposed. The camera is set to correctly expose the main subject of the photo, the bush, leaving the insects overexposed.

So in the first photo, you have some overexposed and out of focus insects in front of a bush. They are so blurred that they overlap, giving an overall cloudy appearance which some people might think looks like a ghost. It would certainly be a puzzle to anyone taking such a photo who hadn't noticed the midges at the time. If I'd told the pass

No comments:

Post a Comment