Shutter speed is one of the must-know aspect of digital photography. To become a successful photographer one should know Shutter Speed, Aperture, and ISO. Shutter speed is the main area where you can express creativity. One can create dramatic effects by either freezing action or blurring motion. So let’s get into shutter speed.
Before going to shutter speed, we need to understand about shutter. So what is shutter? Shutter is a curtain in front of camera’s image sensor(film in film cameras), that stays shut until the camera fires. When a shot is being taken, shutter opens and let the light from outside to image sensor through lens aperture. This is called exposure. After certain period(may be seconds or milliseconds depending upon the shutter speed settings) closes itself and cut the light to sensor. All this exposure process happens when you press the ‘shutter button’.
So we know what is shutter and exposure. Its time to move on to shutter speed. Shutter speed otherwise Exposure time, indicate length of time shutter is open, exposing sensor to light. If shutter speed is fast, we can freeze an action as you seen in the picture below.
If shutter speed is slow, it creates ‘motion blur’. This blurring causes moving objects appears blurred along the motion direction. It is a favorite advertising technic used for cars and motor bikes, as it create a sense of speed and motion in viewers mind.
Slow shutter speed are very helpful in photographing lightnings and other objects in night or low light conditions. Be sure to use a tripod otherwise your image may be shaky. Landscape photographers use slow shutter speed intentionally to beautify waterfalls.
Measure Shutter Speed
We learned fundamentals. Every thing need a units to measure. We measure speed in Kilometers per seconds or miles per seconds. In digital photography shutter speed is measured in fractions of seconds(or in seconds). Shutter speed indicate how much time, the shutter is open. You can see shutter speeds like 1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8 etc. Its best to remember the doubling property in mind as aperture setting also doubles the amount of light. Increasing shutter speed by one stop and decreasing aperture by one stop give you same exposure levels. In some camera, you can set your shutter speed in seconds like 1 second, 5 seconds etc. These shutter speeds are very low and come handy in very low light conditions also for creating some special effects.
Focal Length and Shutter speed
Longer focal length will magnify camera shake in photographs and your images may appear blurry. To reduce those unwanted blurring you can use fast shutter speeds. Common rule of thumb in this situation is to use shutter speed with the denominator larger than the focal length of the lens. for example, if you have a lens of 50 mm, shutter speed of 1/60 is good but your lens in 200 mm then you should around 1/250.
Shutter speed is not a lonely feature, it is related to aperture and ISO. Three of them together know as exposure triangle. As you change shutter speed you will need to adjust other setting too to get a good well exposed image.