Exposure Triangle and Shutter Speed
Have you heard of the exposure triangle in photography? It is an important part of getting your image to look it's best, and all three components of the triangle work together to create a perfectly put together image. The three parts are ISO (back in the film days, it was film speed), Shutter Speed, and Aperture.
Shutter Speed
Let's learn a bit about Shutter Speed first. What is it? The first word, "shutter" is a big part of it. The shutter on your camera is like a barrier to keep light out when you are not photographing, and once the shutter release button is pressed, opens to let the light in. Think of it as a window shutter. When you want light in, you open the shutters, right? When you want light out, you shut the shutters!
So, shutter speed is basically how long an image is exposed to the light; how long the shutter is opened to allow that light in. When the shutter is open, the image is recorded, and when the shutter is closed, it stops recording an image.
Time
So, what happens when the shutter is open for a long time? How much light will enter? If you guessed A LOT, you are right. What about if the shutter was open for a short amount of time? Just a QUICK open and close? How much light will enter? If you guessed NOT VERY MUCH, you are right. Just like the shutters on a window. If they are open all the way for a long period of time, a lot of light gets in. If they are open all the way for just a short amount of time, then only a little amount of light will get through.
Using Shutter Speed
How can you use Shutter Speed with the other elements of the exposure triangle? As mentioned, they work together. If you change one aspect of the exposure triangle, then you need to change the other two or just one of them, as well. First, you need to decide what type of image you want to create? Are you looking to FREEZE ACTION? Do you want to BLUR the waterfall you are photographing? Both will require different shutter speeds.
Are you in a dark room without a flash (not recommended) and need to let a lot of light in? Or, are you outside on a very sunny day and need to let less light in? Both will require different shutter speeds.
FREEZING MOTION OR BLURRING
Do you want to freeze the action? If you look at the image above, you will see both Ianna and James running toward their parents. I used a very high shutter speed to "freeze" them in motion. The general rule of thumb is to use a shutter speed of 800 or higher if you want to freeze action. Remember, the shutter is open longer with a slower speed so it is still recording all the movement until it shuts down. It will record the movement and create blur with a slower speed. But, it will "freeze" the movement with a higher shutter speed-it stops the movement because the shutter is only open for a millisecond!
Remember, any subject could potentially cause blur. Especially if they are moving. If you are taking portraits of children, it is best to use a shutter speed of at least 1/250. Even if they look still, they are still moving. No one can be perfectly still!
To get the best image, don’t use a shutter speed that’s slower than your lens length. What does that mean? If you are using a 200mm lens, keep your shutter speed at least 1/250, for example.
To show "blur", all I had to do was use a slower shutter speed and Ianna and James would have been blurry!
How much light do you have around you?
Where are you photographing? If you are outside at night with barely little light, you need to up your ISO (another topic for the next blog) and lower your shutter speed as much as you can.
If you are outside on a sunny day with a lot of light around you, you need to lower your ISO and up your shutter speed.
For example, the image of Serena was taken outside in bright sunlight. I already had enough light in my area, and I did not need to "freeze' any action. I did need to make sure my image was properly exposed, though. I also wanted to use a smaller aperture to create a more pleasing portrait. So, I needed to up my speed a bit to compensate. I did not need a lot of light, so my shutter could open and close quickly. I chose 1/400 and it worked perfectly.
The image of the barn outside in the dark was another story. With just one large light to light the area (on the barn) I had to up my ISO to 4000. This gave me the option of having a much slower shutter speed so the shutter would be open longer and let more light in. And, I would recommend having a tripod for this kind of shot! It works a lot better.
More Considerations
Keep in mind, shutter speed is just a part of the exposure triangle and all the moving parts need to be working properly to get a correct exposure. Taking the creativity part of the image into consideration is also important. Do you want a "blurry" background? Do you want everything to be in focus? What about composition or the elements of an image? There are so many other parts of capturing an image correctly and creatively.
Learning the exposure triangle first will give you a good understanding of how to properly expose an image and then you can go from there. Getting it right in camera first and learning all the "rules" first will give you a good foundation so you can then go an explore more ways to break them.
Stay tuned for our next blog post, "All about ISO"!
0 Comments