New camera uses eye to set focus

A CAMERA that takes a cue from the position of your eyeball to set its automatic focus should be on sale in Britain within a month.

Canon, the Japanese electronics company, has incorporated an infra red light source into its focus mechanism that shines directly onto the user's eye. The light is reflected back from the cornea onto electronic sensors inside the camera to tell it where your eye is looking within the scene through the lens.

Even advanced auto-focus cameras force users to move the camera to centre a box in the viewfinder over the object they want in focus. Such systems will then focus only on whatever object inside that box is closest to the camera.

Canon's new camera, the EOS (Electro Optical System) 5, lets the photographer focus on anything within the scene, regardless of its distance from the camera. 'This means you can concentrate on the composition of the picture, rather than being distracted by the limitations of the focusing system,' Jonathan Brandon, Canon's marketing co-ordinator for the camera, said.

The system lets you take a series of shots, say of someone moving across a scene, simply by looking at the person rather than having to refocus or recompose the picture. Once the camera has decided its focus point, it does not matter if you blink or look away.

Everybody's eyeballs are a different shape, so the EOS 5 has to calibrate itself to suit each new user. It does this by shining two tiny infra red beams onto the eye and noting the separation between the beams that come back - an indication of the curvature of the eye. It then compares this with separations it holds on up to five memorised individuals.

The system will then compensate for the curvature of each individual's eyeball, to be sure that it is taking an accurate reading of the position of the reflected beam as the area the photographer wants in focus.

As the photographer looks through the lens, they will see five separate focusing areas, spread horizontally across the image. Once the camera has worked out where you are looking, it uses the nearest of the five sensors as the centre of its focus. 'There is no reason why in a few years time we should not have 50 such focus zones, spread across the scene, but at the moment we can't build the sensors small enough to do that,' Mr Brandon said.

The camera will also compensate if the one of its users wears glasses. It shines its beam at the eye at a slight angle to be sure that at least some of the reflected light comes from the eye rather than the surface of the glasses.

Canon said the infra red beam had no safety implications since it operated at about half the power of a typical television remote control unit. The camera body with built-in flash, 'red-eye reduction feature' and an exposure system that can evaluate readings from 16 separate areas of a picture will cost about pounds 500.