3D Television is a general name for systems that provide viewers with a sense of depth similar to that we see in real life, because we have two eyes spaced apart and a highly sophisticated brain. Each eye sees the world from slightly different angles, and the brain merges these two pictures to create a central single image that has 'depth'.

The reason for the sense of depth we see has been understood for over 100 years, and many techniques for recreating for the viewer have been developed. Fundamentally those developed so far have been relatively simple. Two pictures or scenes are shot, one for each eye, and each eye is presented with its proper picture or scene, in one way or another. This is called 'stereoscopy'. Hollywood has made movies like this, and indeed over the past 50 years there have been waves when this falls in and out of favour with filmmakers. At the moment (2008) we are in a wave of favour.

Though the concept of 3D is simple to understand, it is difficult to achieve a 3D system that does not cause 'eye fatigue' after a certain time. Most current higher resolution systems also need special eyeglasses which can be inconvenient. Digital alignment of the stereo pair, possible in our new digital world, can help to reduce eye fatigue, but is not the complete answer.

Apart from eye-fatigue, systems developed so far can also have limitations such as constrained viewing positions. Multiple viewpoint television systems are intended to alleviate this.

Stereoscopic systems also allow only limited 'production grammar' etc. We should not under-estimate the difficulty, or the imagination and creativity required, to create a near 'ideal' 3D Television system that the public could enjoy in a relaxed way, and for a long period of time.

Among the countries where 3D research has been made for many years are the United States, France, UK, Italy, Canada, Japan, Germany, and Russia, though this is far from a complete list. Russia (Prof Mark Krivocheev) made the proposal to the ITU-R that the time was ripe for worldwide agreements on 3D Television, and the ITU-R Study Group 6 has agreed on a 'new Study Question' on 3D Television, which will be submitted for approval by the ITU-R Membership.

The Question calls for contributions on systems that include, but also go beyond stereoscopy, and include technology that may record what physicists call the 'object wave'. Holograms record in a limited way the 'object wave'. Will there be a way of broadcasting to record an 'object wave'? This remains to be seen. No approaches are excluded at this stage.

The 'Question' is essentially a call for proposals for 3D Television. Journals and individuals are asked to 'spread the word' about this, and to invite contributions if possible before October 13, 2008. Such contributions are normally channelled via national administrations, or via the other Members of the ITU – the so-called Sector Members. A list of all ITU member countries is available here.

If you wish more information about making a submission, and/or to participate in the work, you are invited to contact ITU-R by email at rsg6@itu.int.

This Question is being studied in ITU-R Study Group 6 (Chaired by Christoph Dosch, Germany), Working Party 6C (Chaired by David Wood, EBU).

A group within WP 6C (termed a Rapporteur Group) has been established, led by Vittorio Baroncini (Italy), to take up this matter between now and the next meeting of SG 6 WP 6C (please consult the online ITU-R Meeting Schedule).