Understanding aperture and shutter speed pdf

They expressed their frustrations and I totally felt her pain. I have been there before. Several years ago, my two favorite settings were head and the running man the little icon on top of the camera that looks like a head and a marathon runner.

Because they worked. When I wanted to take a photo of a person the head worked great and when I wanted to take pictures of kids the running man was perfect.

Kids run fast. So of course the running man icon made plenty of sense to me. They run and he runs obviously that is the right mode. While this was true. When I was first starting to understand my DSLR it was hard to find the resources I needed to understand what the camera was doing and how to best use it. I would pick up a trick here and there, but never truly understood what the camera was doing or even why I had to change the dial to get the pictures I wanted.

I definitely did not know what aperture, ISO, or shutter speed even meant. I have decided over the next several blogs lets get back to the basics. I am so excited about this because over the years a homeschooling mom. I have learned one solid truth.

In order to lock in things that you have learned you have to go through three steps. First, you learn something new. Then, you do it. Then you teach it. By sharing my what I have learned I will continue to learn and grow. Building a solid base to learn more. On the inside of every camera is a shutter. The shutter opens and closes to let light shine onto the sensor and capture the photo.

The slower the shutter closes, the more light is let in. The faster it closes, the less light is let in. How fast that shutter moves is shutter speed. Lets say you are taking a picture in a room that is not well lite. If your shutter speed is too fast; your image will be underexposed to the light and the image will be dark. If your shutter speed is too slow, then your picture will be overexposed or too the light. And many times we want a special photo that requires us to set some or all of these three variables manually.

The top photo of a girl hitting a softball requires us to set a fast shutter speed to stop action. An automatic setting would have created a blurry effect. The second photo was shot with a large aperture setting such as f1. This aperture setting allows only the flower to be in focus. Our attention is not distracted by items outside the window.

The third photo shows the effect of changes in image quality based on ISO. Remember we increase ISO when there is low light. But it comes at a price. Select subjects, objects, or places that will allow you to illustrate changes in shutter speed, aperture, and ISO. If you have a digital camera create at least 3 images each. Take 3 with changes in shutter speed, take three with changes in aperture, and take 3 with changes in ISO. You will need to change the settings on your camera. If you only have a cell phone camera, take 3 fast moving subject photos, three photos where items are close and far, and 3 photos outside versus indoors without flash.

Comment as noted in 2. Refer to your manual to make each change. Below are three examples. The changes to a scene can be dramatic and amazing to behold with our eyes. Your camera interprets the light reaching the sensor create a digital image file from it. If you have too little light entering the camera, the photo will become underexposed. If too much light enters the camera, your photo will become overexposed.

With the correct amount of light entering the camera, you will get a perfectly exposed photo, with nothing totally hidden in the shadows and without blown out highlights.

Since the amount of light changes during the day, your camera also has to have a way to understand the light and adjust to it. Your camera does this primarily by balancing three basic factors, which is the shutter speed, the aperture, and the ISO.

Shutter speed, aperture, and ISO are the three basic pillars of understanding exposure. In manual mode, your camera helps you evaluate how much light is needed to get a perfectly exposed scene. It tells you what the current setting would result in with the exposure level indicator that you see in the viewfinder or on the LCD screen on the back of your camera.

T he exposure level indicator should be centered to get a perfect exposure. If the indicator is showing negative values, your image will become underexposed and therefore dark. If the indicator shows positive values, your image will become overexposed and too bright with washed out colors. To get a perfectly exposed photo, you should adjust one of the three exposure factors: Shutter speed, aperture or ISO or several of them.

Shutter speed, aperture, and ISO all affect the exposure of a photo. And they do so in relationship to each other. This means that if you change one of them, you have to change at least one of the other to get the same exposure value as before the modification. Let us say you are taking photos of your kids in the garden and your camera tells you with the exposure level indicator that the exposure it perfect. However, if the kids are running and jumping around all the time, the photo might look blurry and unsharp because they move so much.

To avoid this, you can increase the shutter speed which will make your kids appear sharp on the photo. To remedy this, you would have to sacrifice either the current ISO value or your aperture value.

Changing these comes at a cost of either more grainy look as you raise the ISO or a shallower area in focus as you use a larger aperture. The easiest way to understand aperture is by likening it to the pupil in a human eye. The pupil adjusts to control how much light passes further into the eye. If you enter a dark room, the pupil will expand to allow more light to enter.

If you point a flashlight towards your eye or go outside into the sun, the pupil will contract to allow less light to pass further into the eye. Aperture has the same function in a camera lens. It controls how much light enters further into the camera. Your camera is limited to use only one aperture setting per exposure.

You can see this a limitation, but also as a creative constraint to control which areas of your image you want to have in focus. Aperture is measured using the F-stop scale. On your camera, you will see this displayed as i. In the beginning, many get a little confused about aperture values. This seems contradictory.

Below you can see how the aperture works. The potential downside is that the depth-of-field can become too narrow for you to keep your whole subject sharp. In that case, you should use a smaller aperture to increase the depth-of-field. In the image below you can see that the whole jetty and the clouds are in focus. Just remember that there is a cost to using a small aperture. Less light will enter the camera, which means that you have to adjust either the ISO or the shutter speed to compensate for the loss of light when using a smaller aperture.

A narrow depth-of-field helps guide the eyes to where you want the viewer to look, as with the flower which is the primary focal point in the image below. Again remember the cost of using a large aperture, which is that more light enters the camera and affects the exposure.

This can potentially result in an overexposed image, so you have to compensate by using either a lower ISO or a faster shutter speed, or both. If you use auto ISO you will have fewer issues with overexposed images, unless in conditions with extreme amounts of light, as the camera automatically uses a lower ISO, when necessary.

But if the camera is already at the base ISO, and there is still too much light at the large aperture you have set, you will have to compensate by using an even faster shutter speed.

We will dig deeper into controlling the ISO level further down. As you can learn from the exposure triangle at the beginning of the article when choosing one setting you have to compensate by changing other settings to balance the exposure. Shutter speed is the time that the camera allows light to hit the camera sensor. The shutter curtain in a camera compares to your eyelids, except that the shutter curtain is closed as default.

Pressing the shutter is like opening the eyes and closing them again. However, you can do this at varying speed. If it is bright, you only need to open your eyes very shortly before closing them again, and you will still be able to tell, what you saw.

On the other hand, if it is dark, you need to have your eyes open for longer, until you can see something. The light impressions that the camera sensor picks up, during the time where the shutter curtain is open, is what translates into a digital image.

If you get too much light to the camera sensor because a slow shutter speed will result in an image that is too bright, and therefore overexposed. If you get too little light, your image will become underexposed. However, as you have learned above you can balance this out using ISO and aperture. Compact cameras automatically set the shutter speed for you. But in DSLR cameras, you have the freedom to control the shutter speed. This gives you both possibilities for being more creative in your photography, but challenges that can result in poor images.

Shutter speed is measured in fractions of a second for normal photography or seconds for long exposure photography. The longest shutter speed limit, without using a cable release or remote is normally 30 seconds. When you go above 30 seconds by using a cable release or remote control you camera will display bulb because the shutter will be open until you release the cable trigger or press the remote again to stop the exposure.

Landscape photographers often use a slow shutter speed as a way to show the movement in waves, clouds or even grass. This is done by using a tripod to ensure that the camera will remain static, so the movement that occurs while the shutter is open, only comes from the elements in the scene. With a fast shutter speed, you can freeze high motion action, like sport or a racing car. However, a car that is completely sharp will often look as if it is not moving. Therefore, using a slower shutter speed can help you add some energy to your image and show that this car is moving very fast.

You can do this by following the car with your camera, while using a relatively slow shutter speed. This technique is called panning. You can learn more about with these useful tips for mastering panning over at Lightstalking.

With nature photography , you would, more than often, want the subject to be tack sharp. This requires a fast shutter speed.