= 12. Semi-Interquartile Range. The semi-interquartile range of a distribution is half the difference between the upper and lower quartiles, or half the interquartile range. Therefore, from the example above, it was determined that the interquartile range = 12.
Electronic Viewfinders (EVFs) An EVF is basically a very small screen inside a viewfinder, so you can put your eye up to the viewfinder and use it like a traditional camera. On most cameras with EVFs you can switch the view between the viewfinder and the rear LCD screen interchangeably.
The viewfinder was normally a parallel sight within or on top of the camera body. In the 1950s and for much of the 1960s these cameras were powered by clockwork motors, again with variations of quality.