How Does Shutter Speed Work?

Shutter speed, how does it work and what does it do?
Basically it governs the amount of time the aperture will remain open when you press the shutter release button.
It is usually a fraction of a second but it can be much longer than that.
When you press the shutter release button on a camera, you will open the aperture, which will let light into the camera.
That light coming into the camera, is the light that is reflected off the scene in front of the camera at that time.
During the time the shutter is open it will take a picture of the scene in front of it.
In other words it will record the light that is reflected from the scene.
It will save this picture on the sensor, and that will be the photograph.
That action is one of the factors which will decide how the photograph will look.
The amount of light coming through the aperture while the shutter is opened depends on how long it’s opened for.
While this can be from a minute fraction of a second to hours, most photographs are taken while the shutter is open for less than a second.
I’ll use some images to show what different shutter speed does.
In order to do so I’m using a subject that is moving freely and will illustrate the point well.
The props I’m using in these shots are a flag and some shrubs.
They are being blown about by a strong wind so there’s a lot of movement going on.



Examples of shutter speed; 1/1000 second
I took the first set of photos I’m using were shot at 1/1000th of a second.
Some things move so fast that they have to be shot at speeds like this, and faster, to make a sharp photograph.
Those include some birds in flight, racing cars, water cascading down a waterfall.
I know it’s fashionable to photograph waterfalls at slow speeds to get that foam like look, but I prefer the frozen in time look.
I managed to freeze the flag pretty well at this speed, but you can still see that it’s moving very fast.
The other photos are both of shrubs, so to distinguish them I’ll call one a plant, and one a shrub.
I’ll call the one with the berries a shrub and the one without a plant.
All shots were taken with an aperture value of 5, so they have a fairly narrow depth of field.
This means that only a small part of the photograph is sharp, but part of all are.



These one were shot at 1/125 second
The second second set of photos I took at a slower speed.
A second is a very short length of time, but in terms of shutter speed, sometimes it looks incredibly long.
The speed I shot the second photo at was 1/125th of a second, which is a tiny amount of time.
They don’t look very much different to the previous one.
The colour in the shrub photographs is a noticeably brighter shade, the plant less so, hardly noticeable in the flag.
The extra light admitted during the shot is the reason they’re brighter.
The shrub photo is not as sharp, but there’s little difference in the others.



Progressively slower shutter speeds
I shot the third set of images at 1/30th of a second.
There’s very clear movement to be seen in the flag in the photograph.
The movement in the plant photograph is not a clear to see at a glance.
Look for longer than a quick glance though and it’s definitely there.
The shrub photograph shows a marked increase in movement in most of it.
When we look at things with your eyes, it’s hard to grasp how fast the things you’re looking at are moving.
We don’t have the ability to take a snap shot with our eyes, but we do with a camera.
In photographs like this one we can begin to grasp just how fast things are moving.
The shots I took were progressively slowing down.
The fourth set show two at 1/5 and the other at 1/4 of a second.
There’s a lot of movement in these photographs, although the plant one is showing less than the other two.
The end of the flag that isn’t tied is blowing so hard that some of it can’t be seen properly in this image.
The shrub photograph is showing massive movement, with some of it being a blur.



My slowest example of shutter speed
The last set of photos, I took with a two second shutter speed.
You can still see some of the flag, but it’s ghost like, it’s blowing about so fast.
Part of the shrub photo looks sharper than the previous one.
While I used a remote release it looks like there was some camera movement in 1/5 shot.
I hadn’t noticed that while the wind was still blowing so I can’t reshoot, it’s totally calm now.
The plant photo shows more movement but not as much as you’d expect for a 2 second exposure.
The flag and plant photos at 2 seconds are much brighter than the others.
You would only use a shutter speed this slow if you were using an ND filter or if there was little or no light.
I’ve only used a very small selection of the shutter speeds available on a camera.
They generally range from 1/4000th, or even 1/8000th of a second to 30 seconds.
To go beyond that you will have to go to the Bulb setting, which will keep the aperture open as long as you keep the shutter release button pressed.
At speeds slower than 1/60th of a second it’s necessary to use a tripod to avoid camera shake.
That will cause a blur in parts of the photo which are static as well as the moving parts.



Learn more about shutter speed
This is a very short and quick explanation of shutter speed and what it does.
Find out more from these articles, Introduction to Shutter Speed in Digital Photography and
What is Shutter Speed? How Simple Shutter Speed Settings Create Motion in Still Photos.
You can learn about aperture value by reading this article, So What Is Aperture Value?