Shutterspeed

shutterspeed determines how long the film or sensor is exposed to light. This is usually accomplished by a mechanical shutter between the lens and the film or sensor which opens and closes for a period of time determined by the shutterspeed. For example, a shutter speed of 1/125s will expose the sensors to 1/125 sec.

Shutterspeeds is in fractions of seconds, usually a multiple of 1/2, so every shutterspeed will share half the exposure by halving the exposure time: 1/2S, 1/4s, 1/8s, 1/15s, 1/30 's, 1/60s , 1/125s, 1/250s, 1/500s, 1/1000s, 1/2000s, 1/4000s, 1/8000s, etc. shutterspeeds for high exposure expressed in seconds, eg 8s, 4s, 2s, 1s.

Optimal shutterspeed depends on the situation. A useful rule of thumb is to take pictures with shutterspeed on the size of 1 / (focal length) to avoid blur due to camera shake. Under that speed, a tripod or image stabilizer is required. If you want to "freeze" the action, for example in sports photography, you usually use shutterspeeds 1/250s or more. But not every scene needs a high shutterspeeds. For example, following a moving object by panning with the same speed as the object allows to use lower shutterspeeds and can create a background with motion blur.