The 3x optical zoom lens was mounted vertically completely inside the camera body, looking at the outside world via a 90-degree reflecting prism, in the manner of a submarine’s periscope. This meant that the camera could be much thinner - just 20mm - than contemporary models with conventional lenses, and without the delay of extending a long zoom lens it could be ready to take a picture in just 1.8 seconds, which at the time was unbelievably fast and is still pretty respectable today. There have been eight further models in the series, all sharing the same basic core technology.