What is the Shutter Speed?
Shutter speed is a setting that controls how quickly the shutter opens and closes on your camera when you press the shutter button.
For photographers, it is simply a measurement of how fast or how slow the shutter opens before it closes so you can control the amount of light hitting the camera’s sensor. It is measured in fractions of a second up to several seconds. The lower the number, the faster the shutter opens and closes and the less light will pass through the lens. It really is that simple.
How Does Shutter Speed Affect Your Photographs?
The primary factor controlled by the shutter speed is the amount of light your image will have. It also determines how the size of your aperture and your ISO setting to get a proper exposure.
As pointed out in the post about the Exposure Triangle, all three of the settings (shutter speed, aperture, and ISO) have positive and negative impacts depending upon their settings.
For shutter speed, that impact is how it stops or slows motion. The faster the shutter speed, the more motion will be stopped. The slower the shutter speed, the more likely you will see motion. If you have it too slow, it will affect the sharpness of the photo due to picking up movement as you were taking the photo.
An old rule of thumb concerning the lowest shutter speed to use with a particular lens is still somewhat appropriate in modern lenses and cameras which help prevent motion at slow shutter speeds. The old rule was never to use a shutter speed slower than the reciprocal of your lens size. For example, if you are shooting with a 500mm lens, you should never use a shutter speed slower than 1/500 without using a tripod or other support. With modern cameras, you often can push that a bit — maybe up to 2 stops (taking a 1/500 to 1/125) but I still use the standard of 1/500 for a 500mm lens. Yes, I can push it a bit, but I know if I stay at 1/500, I am not likely to have a movement problem that makes my image soft and not sharply focused.
How does this affect you as a nature photographer?
It depends on what kind of photography you are doing. If you are doing macro photography, the more depth of field the better. So, you would want to use a small opening creating more depth of field so more of the flower or insect or whatever subject you were photographing, would be in focus.
If you are photographing birds in flight, depth of field is not usually the critical factor so you may want to have the aperture wide open so you can shoot at a higher shutter speed.
What Shutter Speed Should You Use?
I like to use as fast of a shutter speed as I can unless I am trying to show motion such as with water flowing, or to give a sense of movement to car speeding past. Of course, you have to keep the Exposure Triangle in mind since the shutter speed is a factor in how much light gets to your sensor.
For birds in flight, I try to stay at 1/2000 or higher.
For macro, I use whatever setting is necessary to get the depth of field needed which is controlled by the aperture.
For general photography, it is more subjective. I like to have it as high as I can but balanced with the depth of field I need and the quality of the image as a function of the ISO setting.
When hand-holding the camera, I follow the reciprocal of the lens size, as discussed above.
There are methods and filters for removing noise and sharpening your images. This will be a topic for a later post.