The two standard aspect ratios (ratio of width to height) for commercial and consumer video are 16×9 – which is the new standard for high definition video and 4×3 – which is the old standard for television. (Cinemascope, which is the movie theatre standard is 21×9).
You will start to see all new televeision shows being broadcast to fit the new 16×9 standard. New computer monitors now generally conform to the wider 16×9 format. YouTube – a bellwether for the online video industry – has recently switched it’s video standard to 16×9.
The majority of new commercial and consumer video will be shot in 16×9 format in the future. 4×3 will start to look ‘dated’ in the next few years. You still see many corporate videos being shot at 4×3 – this is because the videos are being shot with 4×3 format cameras or because the company has chosen to continue with an established corporate standard for consistency or to fit into a pre-formatted player.
16×9 is the new standard. I would recommend, where possible, to shoot your corporate videos at 16×9.