The last two weeks we talked about Exposure, and how you can change it by adjusting both the Aperture (opening of the diaphragm) and Shutter Speed, and then more in details about Aperture and how it affects the Depth of Field.
Today, we'll talk more about Shutter Speed.
Just like the name suggests, the shutter speed is the length in seconds between the opening and closing of the shutter, of the diaphragm in front of the sensor of the camera.
A fast the shutter speed will "freeze" the movement.
And inversely, a slow shutter speed will blur any movement of your subject(s).
To be more specific if your subject is moving faster than your shutter speed it will appear blurry, but if your subject is slower than your shutter speed it will appear sharp on your picture.
Being able to control that is really useful if you want to add some action on your images (for example for sport photography).
Most of the time you will probably want to have a fast shutter speed to keep everything sharp, but sometimes it will help the story of your picture to do the opposite.
For example on the photograph above (left), I chose a slow shutter speed to show the stillness of the street musicians contrasting with the movement of the pedestrians around them.
Now, let's go back to the Exposure....
When you have a fast Shutter Speed (for example 1/1000 s), a short amount of light will have time to enter in your camera, and on the other hand a slow shutter speed (for example 1/10 s or longer) a bigger amount of light will have time to enter.
So the choice of you shutter speed will have a big impact on your overall Exposure.
On (D)SLRs cameras you have two modes in which you will be able to change your Aperture:
- M - Manual
- Tv (Canon) / S (Nikon) - Shutter Priority
In Manual Mode (M), you will have to chose both the aperture and the shutter speed to ensure the right exposure for your images. It takes a little bit of practice, so for today let's focus on Shutter Priority Mode, which is another great option to start practicing. In this mode, you are going to chose whatever Shutter speed you want (depending of the effect you want on your image), and your camera will automatically match this speed with a suitable aperture to ensure a good exposure of your picture.
Ready to try?
To illustrate, I took a small object easy to move (and not too fast like a ball): a wooden train.
(and I also use two of my kids as little assistants on each side of the train rack).
I used a train rack to have an object on my picture that will not move, as a reference, to show you that any blurriness on the images will be a consequence of the choice of shutter speed and not of handshaking.
And I used a tripod to avoid any handshake.
In this first image, I chose a very fast shutter speed (1/1600 s). The train is moving from the right side to the left, but because the shutter speed is so fast, you can't see any movement, the train is as sharp as the train track.
Second image, I started to slow down the shutter speed. Here it's 1/250s and you can see that even though the train track is still sharp, the train itself (this time moving from left to right) is starting to appear blurry.
Third image, the shutter speed is even slower (1/80s), and the moving train is even more blurred (the track is still sharp though).
Fourth image, I chose an even slower shutter speed (also called longer exposure) and the moving train is so blurry that you can barely tell what it is (track still sharp).
On the final image the shutter speed is so slow (1/10s) than you can barely see the train (the track is still sharp)
Notice that I could go even slower and make the train totally disappear !!
Your turn to give it a try! :-)
Feel free to use the Comments section to share your images of this exercise, but also to ask any question.
Next time.... ISO ....