What is Shutter speed?
In photography, shutter speed or exposure time is the length of time when the film or digital sensor inside the camera is exposed to light, also when a camera's shutter is open when taking a photograph.[1] The amount of light that reaches the film or image sensor is proportional to the exposure time. 1⁄500 of a second will let half as much light in as 1⁄250.
The camera's shutter speed, the lens's aperture (also called f-stop), the Film Speed (a.k.a. ISO), and the scene's luminance together determine the amount of light that reaches the film or sensor (the exposure). Exposure value (EV) is a quantity that accounts for the shutter speed and the f-number. Once the sensitivity to light of the recording surface (either film or sensor) is set in numbers expressed in "ISOs" (ex: 200 ISO, 400 ISO), the light emitted by the scene photographed can be controlled through aperture and shutter-speed to match the film or sensor sensitivity to light. This will achieve a good exposure when all the details of the scene are legible on the photograph. Too much light let into the camera results in an overly pale image (or "over-exposure") while too little light will result in an overly dark image (or "under-exposure").
Shutter speed can have a dramatic impact on the appearance and quality of photographs, especially when moving objects are involved. For instance a slow shutter-speed often results in a blurred image as the slight shudder of the shutter itself, or the motion caused to the whole camera by the index pressing on the shutter-release button create vibrations that are faster than the shutter itself; this will cause the appearance of the objects in the view-finder and on the photographs having moved when in fact it is the camera that moved.
Good examples of shutter speed
These are good examples of shutter speed because all the main focuses of the pictures are clear and in focus. They are not blurry or over exposed.