Understanding Shutter Speed

Do you know why your photos are blurry?

Is it you or is it the camera?

Last month we covered Aperture, the “hole” in our lens. This month we are moving on to shutter speed, the culprit behind your blurry photos!

Yes, sometimes you cause the blurry photos, sometimes it is your camera. Let’s figure out why.

The shutter is literally a curtain in your camera. It opens and closes letting light hit your camera’s sensor. The sensor acts as the film, recording your photo. The noise you hear when you press the shutter button is the curtain, opening and closing.

The longer the curtain is open, the more movement you capture.

The faster you open and close the curtain, the less movement you capture.

So blur happens when your shutter speed is too slow.

Seems easy enough doesn’t it?

How do you know what is fast enough? Let’s consider two things, your blur and your subject’s blur.

The Blur You Create Through Camera Shake

You create blur when the shutter speed is too slow for you to hand hold the camera. As a rule of thumb, you want your shutter speed to be equal (or greater than) the reciprocal of your focal length.

Let me put it in simple language.

If you are using a 50mm lens, your focal length is 50mm. You want your shutter speed to be 1/50th of a second or faster.

70mm = 1/70

100mm =1/100

200mm = 1/200

So, the longer your focal length the faster your shutter speed needs to be to avoid blur through camera shake.

The Blur Your Subject Creates Through Movement

If you want to avoid blurry photos when your subject moves, we need to look at a second set of shutter speeds and conduct an experiment!

Remember your eyes from last month’s lesson? This time, let’s consider your eyelids. They work as your eye’s curtain or shutter.

Turn a ceiling fan on in your home. Now, look at that fan and blink quickly. What do you notice? If your eyes work like mine, you see the motion of the fan stop.

Look at the fan again, leaving your eyes open for a long time. The fan should be blurred.

If you can control the speed of your fan, you could slow the fan down, now you can blink more slowly and still stop the movement.

So now that your family has stopped commenting on how strange you are, what did you notice?

The faster the movement, the faster the shutter speed needs to be to stop it. Here are a few quick numbers to remember:


1/125 – stops everyday motion


1/500 – stops most children’s motion


1/1000 – stops most bikes, runners and cars

So yes, you may be able to hand hold your camera at 1/50th of a second without shake, but that may not be fast enough to stop the movement of your subject.

But What If I Want Blur?

Not all blur is bad! In fact, you can use motion blur creatively to provide a sense of movement or action in your photos. The blurred foot about to kick the ball across the field. The hands moving in conversation. So many ways to use it creatively.

Extremities always move faster than our bodies. Use the shutter speeds above as a rule of thumb, and then slow them down just a smidge to capture some movement. Want even more fun? Get our your tripod and really play with movement, avoiding camera shake. More details on tripod use with slow shutter speed is a good subject for a future post!

Photos still blurry after following all of these steps? It might be time to check your focus.

Let’s have a little fun with Shutter Speed with an assignment.

  1. Find a moving subject – a fan, running water, a very cooperative bike riding child, a family member willing to jump repeatedly.
  2. Place your camera in Shutter Priority Mode (TV on a Canon for Time Value or S on a Nikon)
  3. Set your shutter speed to 1/50th of a second. Displayed as 50 in your viewfinder. Your camera will determine the aperture.
  4. Shoot.
  5. Change your shutter speed to 1/125th of a second.
  6. Shoot.
  7. Change your shutter speed to 1/500th of a second.
  8. Shoot.
  9. Change your shutter speed to 1/1000th of a second.
  10. Shoot.

Compare your photos. What do you notice?

Share the tricks you use to remember your shutter speeds.