'I only noticed it when I got home ...' This is a phrase often repeated to introduce odd, anomalous or paranormal photos. Despite the fact that digital cameras have a screen on the back that allows you to review photos when you take them (which is extremely useful), people still often only notice oddities when they get home and use a big screen. Of course, by then it is impossible to check what might have caused the strange photo unless you have taken a lot of others at the same time - ideally from different angles and viewpoints.

Typical photographic oddities only noticed at home include:

• orbs - there is a huge amount of information on these starting here
• UFOs - see here for a UFO gallery
• people or objects not noticed at the time - see 'that parrot wasn't there ...'
• ghosts - see here
• oddities like strange mists, weird glowing shapes, mysterious shadows, light trails
• things that just don't make sense!

This article is about the final category - things that don't make sense! All the other categories involve something additional in the photo that wasn't noticed at the time. But there are photos which, though they may look alright at first glance, somehow don't make sense. Here is an example.

The photo clearly shows a woodpecker in a leafless tree. The bird is in the topmost branches of a tree some 15m tall. So, where was the photographer when this photo was being taken? It is not a trick question. The photographer was holding the camera, in case you think it was a webcam on a stick! It looks as though the photographer is level with the bird so they must have been in an adjacent tree or, failing that, in a building nearby. In fact, the photographer was on the ground at the bottom of the tree!

So why does it look as though the photographer was at the same height as the bird? It is an illusion caused by the fact that we are used to seeing photos taken on the level. As there are no clues in the photograph to show what is really vertical (like a building), we unconsciously assume the bird is vertical. And the bird appears vertical because it is parallel with the plane of digital sensor in the camera. And the bird is not upright because it is clinging to a branch which is leaning out at an angle from vertical (see diagram below) towards the photographer.

Woodpeckers live almost entirely in trees and they are used to moving around by clinging to branches and the trunk. They are not as bothered about standing upright as most other animals, such as humans, are. They are quite at home standing at an angle. Their claws allow then to stand at an angle, relative to the branch they are on, so that they can peck it.

In the diagram, the lower camera shows the typical way most people take photos. At that angle, verticals are truly vertical and the horizon really horizontal! However, the upper camera is pointing up at the tree at an angle to the horizontal. It is at the same angle to the vertical as the overhanging branch it is pointed at. This means that the branch will look vertical. Also, any Woodpecker clinging to the branch will also look vertical. Because there are no truly vertical objects in the frame to compare with, our brains assume the photograph must have been taken at the same height as the Woodpecker. This would have put the photographer floating in space next to the tree!

This is just one of the oddities, optical illusions and strange things that you might pick up in a photo once you arrive home.

© Maurice Townsend 2007