SMPTE, the Society of Motion Picture & Television Engineers, holds its annual conference in October. One of the new ideas emerging from it this year is the ‘variable picture rate’ – put forward by Hollywood movie director Douglas Trumbull (pictured). The principle may also be considered in future by the EBU group on Beyond HD.

Today, television and movies have a fixed number of images per second – 50 or 60 for TV and 24 for movies. With today’s electronic cameras, much higher picture rates are possible, such as 120 images per second. Similarly, television and cinema screens should be able to cope with higher picture rates.

The idea here is to have a system which works end to end with a basic rate of 120 images per second. But the difference would be that a varying number of those 120 images may be identical or different.

The relative proportions could be determined by what type of movement there is the scene, and the ‘look’ the producer wants to create. Static images could have lots of identical pictures, as would scenes that the director wants to look like they were shot on film.

The eventual bit rate needed after compression will be influenced by how many different pictures there are per second, so the scheme could give more artistic freedom to programme makers, and possibly minimize transmission bit rates.

From idea to reality will clearly take time, but the approach may represent a creative and technical step forward. Time will tell.