Understanding Shutter Speeds
Shutter speed works hand in hand with aperture and ISO to balance the perfect exposure.
Shutter speed rating varies from 30 seconds through to 1/8000 seconds. Some cameras also feature a "bulb" setting which keeps the shutter open as long as the shutter button is depressed. Traditional SLR cameras often used a shutter release cable which locks the shutter open indefinitely.
The longer the shutter speed, the more likely you are to introduce vibration and motion blur to an image, however, you can capture the motion of objects. The faster the shutter speed, the less blur and motion blur will be captured. With a fast shutter setting, you will "freeze" an object's motion. An example of this can be seen below.
Shutter speeds are given in specific increments which are double or half the previous. For example, 1/125 is half the speed of 1/250 and 1/500 is twice as fast as 1/250.
Controlling exposure is a balance between shutter speed, aperture and ISO and this balance is called the exposure triangle.
Using Bulb mode for super-slow shutter speeds
Bulb mode can usually be accessed by selecting "B" on the mode dial, or on "M" and selecting bulb on the shutter speed selection. The shutter will now be open for as long as the shutter is depressed. On modern DSLRs, this may cause camera shake as you will need to hold the button in. For this reason, you can use a remote shutter release cable which is either a manual switch or a more advanced timer device.
Bulb mode is much simpler than it sounds, but the small matter of knowing how long to hold the shutter open for puts people off using it. If you were shooting a landscape with a 10-stop ND filter, then the exposure chart supplied with the filter, or a downloadable smartphone app will give you an idea. Otherwise, it's a bit of trial and error.
For photographing star trails or time lapse night scenes you may be interested in the article "How to take long exposures on a Canon dSLR".
Example Use of Shutter Speeds
|1/4000||Freezing really fast moving objects such as a tennis ball, football.|
|1/2000||Freezing the flight of birds without blurring the wings.|
|1/1000||Freezing very fast moving objects, such as moving vehicles.|
|1/500||Freezing fast moving people, such as runners and cyclists.|
|1/250||A great speed for freezing your still subject, without having to think too much about focal length and how that affects the motion blur. Great for portrait photography.|
|1/125||You won’t typically want to go much slower than this if you’re shooting hand-held, otherwise, you will likely capture motion blur from your hands.|
|1/60||Again, this is a great speed for panning photography, and handheld photography in low light.|
|1/30||This is about as slow as you will want to go while capturing panning photography, as much slower and your photo will become too much of a blur.|
|1/15||Mounted on a tripod, at this speed you can capture sight movement from moving objects. Think people walking, cars moving in traffic, water blurring slightly.|
|1/8||Capturing motion blur in water.|
|1/4||Blurred movement in a scene. Not so little that it appears accidental, but not so much that it’s hard to tell what’s going on.|
|1/2||More motion blur, only much stronger than before. Think of water starting to appear like mist.|
|1 Second||Twilight photography. The sun may not be completely gone, but there’s not enough light to make up the exposure you’re looking for. You may incorporate a flash, and you’re more than likely using a tripod.|
|> 1 Second||This is where night photography starts to come into play. You can play with different speeds and capture awesome night time photos.|
|Bulb||This is used for exposures longer than 30 seconds, where you can manually control the exposure time with the shutter release. This is used for astrophotography where you may want to capture some stars. You may also use this mode for slow sync flash where you want to have immediate control of the shutter speed.|