Simply put, shutter speed is how long your lens remains open. It is this setting along with ISO and aperture that give the desired effect in photograph. While each of these settings has a purpose, it is the shutter speed that gives us the ability to stop action. By using the settings correctly you can not only stop action, but blur action as well. It’s all about using the right shutter speed to catch the photograph you are trying to create.
The information I am about to show you represents the classic way a camera has been run. I say classic because digital has allowed us to have more choices than the ones I will show you. But, if you understand the relationship between the numbers, the new choices the digital age gives us will only offer you more opportunities to get the image you want.
Shutter speeds start at a timed setting historically called “bulb” and is designated by a “B”. The bulb setting allowed you to keep the shutter speed open as long as you like. This is especially helpful for night photography or extremely low light.
From there things are set up very logically. The next setting would historically be “2”. This is ½ of a second. The one and / are implied. Next 4 which equals ¼ of a second, 8 = 1/8th , 15 = 1/15th, 30 = 1/30th, 60 = 1/60th and so on. Now if you look at these numbers you will notice that each number is related to the other numbers that surround it. 1/15 is twice as much time as 1/30th, which is twice as much time as 1/60 th of a second. This means that every time you change your shutter speed to one of it’s neighbors you are either doubling or halving your light. A change from 1/30 to 1/60th of a second means you are only letting the shutter speed open for half the time (1/30th being a longer time than 1/60th of a second). If you went the other direction and started with 1/60th and changed to 1/30th of a second you would be adding twice as much light.
So, while it might not seem logical at first, once you can accept that the numbers actually represent a part of a second it is easy to accept that there is a relationship between the numbers, and the higher the number the faster the shutter speed.
Now you may be saying…Hmmmm…doubling your light….where have I heard of that before? There is another way to double your light that we have looked at and it was ISO (or ASA for the old folks here).
There relationships between the numbers in ISO also allows you to double your light…right? 100 is half as sensitive as 200, 200 half as sensitive as 400 and so on. Now we have two ways to double the light
hitting either the film or sensor as the case may be.
But shutter speed is not really about how much light we are letting in…it’s about how long your lens is open, it’s about how we are able to stop action. A high shutter speed stops action. A setting of 1/500th (500) will allow us to take a picture that will stop action better than a shutter speed of 1/60th of a second.
Remember that we are working in parts of a second. The higher the number the better it will stop action. Of course like anything else after a certain point it doesn’t do any good to stop it better.
Ok, so how do you use this information? Well, it’s like this. First thing to do is decide what you would like your image to look like. Do you want that basketball player to stop in midair and be crisp, then you need to be shooting at a high shutter speed to stop the action. If you want to make the player blur by you would choose a lower shutter speed…more time for the lens to remain open , more time to the accept the information. More time to allow your subject to move.
While choosing a shutter speed seems intimidating at first, just remember, all you are choosing is how to stop action. That’s it.
If you look around the room you are sitting in you will see that the room is lit all the same. But in reality each section of the room is lit differently. Shadows, textures, reflectivity etc all play a part in what eye and camera see. A light meter will help get a more accurate reading, but only experience can help you use that information. Learning how to get predictable results with basic equipment is more important than having all the do dads. In fact the do-dads only get in the way. The light meter in the camera is all you need for now. Learn how to use the information it gives you!