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What Is the F-Stop on a Camera?
The F-stop is a camera function that lets you control the depth of field (the area within which things appear focused) in order to blur the background behind your subject. When taking photographs outdoors, you need to think about the effect of the light, and whether you want the subject to be in sharp focus or blurred.
When the light is softer, the background will be blurred. The brighter the light, the smaller the area that is in focus. If you choose a shutter speed fast enough for a flash to be used, the image will also be frozen. There will be no blur. However, the shutter speed will need to be slow enough for the whole picture to be in focus.
A F-stop is a variable which controls the amount of light that passes through the lens of a camera to allow it to be used at different settings. The f-stop is adjusted by the photographer while the shutter is open and the aperture is adjusted using the diaphragm blades inside the lens. To find the f-stop for a particular shutter speed you need to use the chart below:
As the shutter speed is reduced to slower speeds the number of f-stops available to the photographer increase. You should always use the widest aperture possible to get the best image. However, if you use a small aperture, such as f11 or f16, it is essential to get close to your subject otherwise you risk blurring the background.
You should also use the highest ISO setting available to you to ensure that your image is not underexposed. You should also make sure that your camera has a good tripod and you are standing still when taking photos. This will help stop the camera shaking which causes unwanted blurriness in your images.
What does ‘F’ mean in F-Stop?
In fact, the F in F-Stop means ‘fixed’. It means that the f-stop value remains constant throughout a scene, regardless of the brightness of the light. As the f-stop number increases, there is a corresponding reduction in the amount of light allowed into the camera.
Why use F-Stops?
For photographers, the main reason to use f-stops is to control the depth of field – the distance in front of and behind the focus point in the image plane where objects appear blurred. The greater the f-stop number, the greater the blur will be across the image.
A photographer can decide how much blur to use by varying the aperture size (the opening through which light passes). If the f-stop is high, then the light will be stopped down and the aperture will be small. The smaller the aperture, the more light will pass through the lens and so there will be a greater intensity of light hitting the camera’s sensor. The greater the light, the larger the depth of field will be.
Aperture vs. F-Stop
To understand how f-stops affect the amount of light that reaches the camera, it is necessary to understand how apertures work. In a conventional lens, such as the 18-55mm kit lens for the Canon EOS 500D digital SLR camera, there are two main components – the front element (lens) and the rear element (diaphragm). The diaphragm is a ring of plastic or metal that stops the light entering the lens.
Normally, a camera’s automatic settings will make sure that the diaphragm is set to the widest aperture available. This allows a maximum amount of light to reach the camera. If, however, you wish to adjust the exposure, you can open the diaphragm up using the shutter speed dial. If you move it to the widest setting, you will increase the amount of light passing through the lens and so will allow a wider aperture to be used.
So, for a given focal length and f-stop, the aperture setting will affect the amount of light hitting the sensor. By adjusting the aperture, you can control the amount of blur in the image.
The relationship between f-stop and depth of field
When you change the f-stop setting on your camera, you are changing the amount of light entering the camera. If you are shooting at the widest aperture possible, then you are allowing the maximum amount of light to enter.
This will result in the most detail being captured on the subject. However, the light will be diffused and so the background will be brighter. It is important to remember that the wider the aperture, the more light that will be passing through the lens. As a consequence, the blur effect is increased and so the depth of field will be smaller.
Conversely, if you are using a narrower aperture, then the light will be restricted. So less of the image will be illuminated. This will cause the background to appear darker. The blur will be less and so the depth of field will be bigger.
The concept of depth of field can be applied to any situation, including portraits, landscapes and macro images.
It is a great aid to photographers who wish to capture images of their subjects that are sharply focused from foreground to background.
What are the different types of F-Stop?
There are two standard F-Stop settings that are commonly used. They are f/2.8 and f/5.6.
The difference between these two values is that, while f/2.8 represents half of the maximum aperture, the f/5.6 setting is equivalent to the full aperture of the lens.
In other words, if you are using an f/5.6 aperture, then the camera’s diaphragm will be set to the maximum size. With the f/2.8 aperture, you will be setting the aperture to half of the maximum value.
There is a third, more rarely used setting of f/11. This has no equivalent in the physical world but is useful in photography.
How do I use F-Stops?
If you are shooting a landscape, you will generally be using the widest aperture possible, which would normally be f/2.8. However, if you are using a wide-angle lens, then the wider you open the aperture, the more distortion in the picture. This is because of the way that the lens bends light.
If you have a zoom lens and want to shoot from a distance, you can choose to close down the aperture, which will restrict the amount of light coming through the lens.