= 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.
Viewfinder: Viewfinder is a slot in the camera which allows you to preview the scene. The Shutter: The shutter covers the sensor (or film in case of a film SLR). The shutter opens up when the shutter-release button is pressed to allow the light to fall on the sensor/film and create a capture. The speed of the shutter can be controlled which determines how long the shutter is open and what amount of the light passes through.