Facial twitch: I believe these twitches are similar to the twitches people get in their eyelids. Usually it goes away within 6 weeks or so. There are other causes such as caffeine, stress, alcohol, electrolyte imbalances and excessive fatigue. Feel better.
A shutter speed of 1/30 for example will let in twice as much light as a speed of 1/60 since it is two times slower. When you decrease the shutter speed by a factor of two you are increasing the amount of light by one stop. Remember that fractions get larger as the number on the bottom gets smaller.
Shutter Speed. 1  Shutter speed is a measurement of the time the shutter is open, shown in seconds or fractions of a second: 1 s, 1/2 s, 1/4 s â¦ 1/250 s, 1/ 500 s, etc. The faster the shutter speed, the shorter the time the image sensor is exposed to light; the slower the shutter speed, the longer the time the image sensor is exposed to light.