Picking the screen aspect ratio is an important decision. Changing it is difficult, because it is more than just a simple format adjustment: a long rectangular slide is built up completely different than an almost square 4:3 one. The origins of the 4:3 screen size go back to IBM punched cards: they were 12 rows high and 80 columns wide (see the image attached to this post), a 25x80 screen could nicely fit 2 of those (computers in the early 70s). Only untill recently, we have been stuck with this aspect ratio. Why do I like widescreen:
  • I like the "movie screen look" better
  • The human eye is more capable of digesting rectangular screens (the reason why Holywood switched over) than square ones
  • It is already adapted for use on big LCD screens, more and more available in conference rooms, exhibition centers and increasingly present in PC monitors or laptop screens.
  • I like the long format better for "left-to-right" slides, showing a logic in 3 steps that flow from left to right (fitting nicely with the rule of thirds). Also, it supports long slide message titles that still fit in 1 line.