*Disclaimer- I've been sitting on this post for a couple weeks but keep forgetting to go out and take the photos as examples.  I'll update when I do that, but wanted to get the post up! Sorry I'm a giant loser. 

Shutter speed is a measurement of how long your shutter is open when taking a picture. This is the amount of time that the photo is being exposed.  Or, more simply- the amount of time that light is allowed to pass through the opening (the aperture!  Check out this Snap!torial to explore aperture).   Logistically, this is a simple concept.  So why does it matter?  Your shutter speed creates – or stops- motion in a photograph.  Effectively, the shutter speed controls how you capture movement.   

You can control the shutter speed on your camera when shooting in S (Shutter Speed priority) or M (Manual) modes on a DSLR by toggling to the desired aperture.  Consult your user manual for how to do this with your specific camera model.  The shutter speed is a function of your camera BODY, so the capabilities don’t change with fancy lenses.    Shutter speed is notated in seconds, typically 1/n, where n is a number… ie 1/100 means 1/100^th of a second.  If you see whole numbers for the shutter speed, those are whole seconds.  BULB (or B) means that the shutter will stay open as long as you are pushing the button.

Most of the time for portrait photographers like me, you don’t want to show any motion.  Not to say you don’t want your subject to be in motion … I mean come on, have you ever tried to get an 18 month old to sit still for a photo session?  What I mean when I say that I want to eliminate motion is that I want the shutter to fire fast enough that there is no detectable movement/ blur in the moving parts of the photo.     

To stop motion, there’s a few general rules to live by for the MINIMUM shutter speed (the slowest).  If you go below the minimum, you’ll see blur in your photo, no matter how sharp the focus.  The blur isn’t from the focus, it’s from the movement.  Note that these are minimums. 

• Minimum to stop general motion- 1/80 or 1/100.  This is my own rule and other photographers may not agree, but I never ever ever ever get little kids to sit still enough to go any slower than this.  Add in that when chasing around a kid, I’m also introducing motion myself with my movements.  So, unless I’m photographing a static object using something to steady my hands, I try to stay at or above 1/80 or 1/100. 
• Handheld rule-  To eliminate the blur from the shake in your hand when you’re holding the camera, the slowest shutter speed should be 1/the focal length of your lens.  Example-  if you have a 55mm lens, minimum shutter speed should be close to 1/55, which would be 1/60.  This rule doesn’t matter much for short (no zoom) lenses, since the earlier rule will trump it, but for zoom lenses, it really does matter!  If you zoom in to use a 200 mm lens, you need to do a minimum of 1/200 shutter speed to eliminate handheld blur. 
• Sports- For sports, the action is fast, so you need to up your minimum shutter speed.  Depending if you’re at a little league game or professional, the speed may differ.   When photographing my nephew’s football, I try to stay above 1/500 to stop the motion.  For a college game, I'd probably bump that up to 1/1000.  Play around and check photos to make sure you’re stopping the action,  adjusting as needed!

Other types of photography want to show motion, not stop it-  for instance, those cool pictures of a car or motorcycle speeding by when the car is sharp focused, but the land it passed by during the exposure is blurred.  Or the many many cityscape photos with the long blurred red lines showing the movement of traveling cars.  In these photos, the desired effect is achieved with a slower shutter speed.  Allowing the shutter to stay open longer means that the motion during that time will be captured in the photograph.   In the examples I described, you are capturing the motion in 2 different ways.  In the first example where you see a moving object sharp and the background is blurred from the motion, the camera actually moves with the moving object. You physically move/ rotate the camera at the same speed that the moving object passes by.  For the second example, you're showing the movement of the car by keeping the camera still, on a tripod, but keeping the shutter open for a few seconds.  Slower shutter speeds will introduce handheld blur, so you should use a tripod or some other object to steady the camera.  

In later Snap!torials, we’ll explore the effect of flash on these long exposure photographs-  adding in a flash either at the beginning of the exposure or at the end will essentially stop the action for the fraction of a second that the flash fires, but then the rest of the motion will show as a blur.  Back in school, this was a fun concept to play with, so I’m looking forward to writing THAT Snap!torial! 

The next Snap!torial will put the concepts of Aperture and Shutter Speed together to get the correct exposure with the desired effects. 

Happy Shooting!

Cara