So you’ve had your new SLR digital camera for a while and have become comfortable with the automatic mode and are now ready to start putting some creativity and control into your pictures, though you are not completely ready to throw your camera into fully manual, the semi-automatic modes may be the way to go. The two semi-automatic (or semi-manual) modes are shutter priority and aperture priority. Of course before you can shoot in these modes you first need to understand aperture and shutter speed. Aperture and shutter speed are the two primary controls your camera uses for exposure. Exposure is the amount of light that reaches the camera sensor. In photography, we are looking for just the right amount of light to show off the details of our images. If too much light, then the picture is overexposed and the details will be washed out or blown, which basically means that it is too bright. If too little light then the picture is underexposed and will appear too dark. We will later discuss how aperture and shutter speed together play a role in proper exposure, but in this blog entry let’s tackle shutter priority mode and shutter speed.
With your SLR digital camera set to shutter priority mode, it allows you to manually control your shutter speed while the camera chooses all of the other settings (aperture, ISO, white balance, etc). To set your SLR digital camera to shutter priority turn your mode dial to S or TV, now you can rotate your main dial to the shutter speed that suits the image you’re capturing.
So what is shutter speed you ask? Shutter speed is the amount of time the camera sensor is exposed to light. Basically, it is a measure of how long your camera shutter is open for. Shutter speed is measured in seconds and looks like 1/500, 1/250, 1/2 or 1 as in one second etc. The longer the camera shutter is open for, the slower the shutter speed, and the more light we capture. For example a shutter speed of 1 sec stays open longer than a shutter speed of 1/500th of a sec, thus allowing for more light to reach the sensor. What this means is that if you are in sufficient lighting (and we’ll talk in later posts about how to find the right light) you can use a faster shutter speed because there will be adequate lighting reaching your sensor, where as in a dimly lit situation you will need to allow more time for the light to reach your camera sensor, thus you will need to have your shutter opened for a longer time, which means a slower shutter speed. Got it? It will get easier the more you practice.
Of course, shutter speed plays an important role in getting proper exposure, it is however, also used to obtain certain effects in the image you are capturing. For example slow shutter speed is used to create a sense of motion where as a fast shutter speed is used to freeze action. Slow is any shutter speed 1/2 sec. to 1/30 sec. Fast is any shutter 1/60th sec. to 1/500 sec. However, keep in mind when you use a slow shutter speed, you will have to contend with camera shake and will more than likely need to use a tripod to avoid this.
Take the images below. The first one was shot at 1/500th of a sec. Which is a fast shutter speed. In this picture the fast shutter speed was used to freeze the motion, as evident in the water. You can see each individual water bead. Where as in the second picture, it was shot with a slow shutter speed of 1/30th of a sec, thus creating a motion/flow in the water.
Here are some short tips for using shutter speed in digital SLR photography (taken from http://www.slrphotographyguide.com)
- Slow shutter speed, slows motion.
- Fast shutter speed, takes the image almost instantly as in frozen in time.
- Use slow shutter speeds of at least 10 seconds or more for night shots of cities, buildings and streets etc.
- When using a slow shutter speed it’s also a good idea to use a tripod and remote shutter release to avoid camera shake.
- If for any reason you don’t want to use a tripod, then a general rule to avoid camera shake is to never set your shutter speed slower than the reciprocal of the focal length value. For example, if your lens focal length is set at 50mm then don’t use a shutter speed any slower than 1/60th of a second and so forth.
- To photograph a running child or animal while blurring the background, set the shutter speed to between 1/40 sec and 1/125 sec. Then follow the running child or moving animal as you press the shutter button. This is often referred to as panning.
Get your camera out and “experiment so you can fully understand this mode of photography. Find some running water and try both fast and slow shutter speeds so you can see the results for yourself. Over time, setting the correct speed for any specific circumstance will become second nature.” (http://www.slrphotographyguide.com) Until next time…happy shooting.