SHOOT: Shutter Speed explained simply

I hope you haven’t been shying away from learning about shutter speed, because it is by far the easiest concept to grasp in the three-legged exposure triangle. Shutter speed affects exposure and subject motion. Aperture and ISO are the primary settings I adjust to control exposure. I only tweak shutter speed when I want to control subject motion. So in my mind the gist of shutter speed is really as simple as knowing whether you want to stop motion in your images, or if you want to blur motion. That’s it! Seriously.

I believe it is important to get the basics under your belt first. Once you understand what the shutter is and how it works, the whole idea of manipulating shutter speed in camera becomes way less scary. The shutter is a flap that sits in front of the camera’s sensor. When this flap is open, light enters the camera and reaches the sensor. When the flap is closed, light cannot reach the sensor. The flap is like a door to a house. When the door is open, guests can enter inside. When the door is closed, the guests are out of luck.

Shutter speed is simply the time the shutter in your camera is open or closed. At varying shutter speeds, the shutter is open for different amounts of time. The longer the shutter is open (i.e. slower shutter speed), more light can enter your camera. When the shutter is open for a shorter amount of time (i.e. faster shutter speeds), less light can enter. If the shutter (door) is open for a long time, lots of light is able to enter. If the shutter (door) quickly closes, the amount of light that can slip in is reduced.

You recently learned about ISO and aperture in the previous installments of the Brave Manual Mode series, which are the other components that control the exposure of your images. With all three tutorials under your belt, I hope you are beginning to see that changes in one area of the exposure triangle affects other areas. If more or less light hits the sensor, ISO and aperture may require adjustment to create a ‘proper’ exposure. Without enough light, your images will appear underexposed (too dark). If too much light hits the sensor, your images will appear overexposed (too bright). I’m careful about mentioning proper exposure because I believe exposure is subjective – there is no correct exposure as photography is an art beholden to the photographer behind the lens.

Now back to subject motion….. Faster shutter speeds will stop motion in its tracks – FREEZE. Slower shutter speeds will not stop motion – creating a BLUR of motion in images. If your subject is not moving, then shutter speed really doesn’t matter much, does it? For gardeners shooting stationary flowers and tomatoes, relax…..shutter speed won’t be your biggest worry. All you really need to be concerned with is not lowering shutter speed so much that camera shake becomes a problem. Camera shake occurs when you are holding your camera and can introduce a slight blur in your images. But a simple little rule will help prevent you from doing that. Never shoot at a shutter speed that is lower than 1/focal length of the lens you are shooting with. What?! Let me explain. So, I shoot with a 50mm lens most of the time. That means when I’m shooting with this lens, my minimum shutter speed is 1/50. Camera shake is more noticeable with longer lens, but this practice is now ingrained in me so I apply it no matter what lens I am shooting with.

Let’s look at few photos to illustrate the concept of shutter speed.

I shot the photo above at a shutter speed of 1/160 sec, At this slow shutter speed, the motion of the water coming out the hose is blurred. Look closely at the trail of water drops streaking across the image.

Next, I increased my shutter speed to 1/4000 sec. If you look at the photo caption, you’ll see that I had to adjust my ISO to compensate for the quick shutter (door quickly closed) and reduced amount of light hitting the sensor. My aperture remained unchanged at f 5.0. At a much higher shutter speed, I was able to freeze the water droplets. Again, look closely at some of the tiniest droplets that are frozen here. Remember the droplets appeared as streaks across the frame at the slower shutter speed above.

The easiest way to master shutter speed is to practice. If you can catch a butterfly or bee in your garden, grab your camera and take some practice shots. If pollinators aren’t abundant, grab your kid, spouse or a friend and practice with a water hose. Photographing moving cars on a busy highway is another great way to practice shutter speed. I’ve done that too!

Happy shooting!