Exposure – Shutter Speed
In the last section we talked about Aperture and how we use it to control the amount of light and depth of field of our photos.
Now we are going to look at Shutter Speed and how we use it to control how long the light hits the camera’s sensor or film. These shutter speeds are in increments of time from 30 seconds to 1/8000 of a second. Most consumer level DSLRs and some advanced compacts top out at around 1/4000 of a second (still pretty fast huh?). Another time setting that most cameras have is called BULB which lets you keep your shutter open for as long as the shutter is depressed. Bulb exposures are usually taken with a remote shutter release cord.
So, how do you use the Shutter Priority (S or Tv) to produce creative photos. Let’s use an example similar to the one in our discussion of aperture. I am taking a photo of a waterfall in program mode. The camera’s meter tells me it is using the following settings: Aperture of f4, Shutter Speed of 1/60sec. at an ISO of 200. A shutter speed of 1/60 of a second is going to freeze the motion of the water, as it falls, more than we may want. I need to slow my shutter speed to make the water look smooth and surreal.
If the range you need to slow down the shutter speed is greater than what is available, through Aperture or ISO, you can add filters that cut the light further. A circular polarizer will give you about 1 to 2 stops and neutral density filters can cut the light even further. Neutral density filters can be purchased in different densities usually referred to in #X designations. For example a 2X will cut 1 stop of light a 4X-2stops, etc. They can also be stacked to increase the density.
What if you are taking photos of something moving like a car, a plane, a motorcycle or your child’s soccer game and would like to stop the action. Well you need to increase your shutter speed, the setting will be totally dependent on how fast the subject is moving.
In the example to the right of the F-18 fighter, I used 1/400 of a second to capture it in flight. Of course when you increase the shutter speed you also need to open up the aperture to allow the exposure to remain constant. If you open the lens up as wide open as it will go your only other control is the ISO setting. P.S. There are no filters to add light to the equation so the trilogy is all you’ve got.
Beware of increasing your ISO too far as the photo will have more “noise” (little specks - kind of like individual grains). The latest camera offerings are getting better and better at noise control, at the higher ISO settings, so you might get by with higher numbers. I try to keep my cameras ISO setting below 1600, but then I don’t’ really like “noise” at all. I guess you could call me “noise” snob. The reason is that I don’t like the look of excessive post processing noise reduction.
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Hi, good post. I have been wondering about this issue,so thanks for posting. I’ll definitely be coming back to your site.
Thanks for the kind words. Please, do come back. I hope to add some new content soon.
Dave