There are three pillars of photography
- Aperture
- Shutter Speed
- ISO
Aperture
Is the opening in the lens of a camera. It controls how much light is passes in through the lens. Which means, a larger aperture allows in more light, while a small aperture allows I less light. Simply put, it works like the iris in your eyes which either expands or shrinks, controlling the size of your pupil, as we move from bright to dark environments. Aperture can add dimension to your photos by controlling depth of field.
Aperture has many effects on your photographs. One of the most important is the brightness, or exposure, of your images. As aperture changes in size, it alters the overall amount of light that reaches your camera sensor – therefore the brightness of your image. A large aperture (wide opening) will pass a lot of light, resulting in a brighter, sharp and focused photograph. A small aperture (higher f number)on the other hand, makes the photo darker.
Depth of field
Depth of field is the effect of aperture. Depth of field is the amount of your photograph that appears sharp from front to back. Some images have a “thin” or “shallow” depth of field, where the background is completely out of focus. Other images have a large or “deep” depth of field, where both the foreground and background are sharp.
A large aperture results in a large amount of both the foreground and background blur. This is suitable for portraits, or general photos of objects where you want to isolate the subject. A small aperture results in a small amount of background blur, which is suitable for landscape and architecture shots.
Aperture can be expressed as a number known as “f-number” or “f-stop”, with the letter “f” Appearing before the number, like f/8 or f8. Lower number means larger aperture (letting in more light), and higher number being smaller aperture, (letting in less light).
Shutter Speed
Shutter speed is responsible for two particular things: changing the brightness of your photo, and creating dramatic effects by either freezing action or blurring motion. Experimenting with different shutter speeds can be very beneficial to your photos, and can affect the overall exposure of your photo.
Shutter speed can be defined as the length of time a camera’s shutter is open, exposing light onto the camera sensor. Similar to aperture, the longer the shutter speed, more light is let in through the lens, and the faster the shutter speed, less light is let in. By adjusting the shutter speed you can control the movement of your subject moving through your frame. Shutter speed is measured in fractions of a second, when they are under a second. For example ¼ means a quarter of a second, while 1/250 means one two-hundred and-fiftieth of a second (or four milliseconds).
Shutter speed and exposure
The other important effect of shutter speed is on exposure, which relates to brightness of an image. If you use a long shutter speed, your camera sensor gather a lot of light, and the resulting photo will be quite bright. By using a quick shutter speed, your camera sensor is only exposed to a fraction of light, resulting in a darker photo.
ISO
Acronym for International Standards Organisation. This is nothing but sensitivity of the digital sensor in your camera to light. When film rolls were used in the past, a different roll had to be used to change the ISO. But now, it easy with a click of a button. We see what is ISO all about and how it affects the pictures we take.
ISO is one of the most important settings on a digital SLR (DSLR) camera, in addition to Aperture and Shutter speed. All these factors affect the exposure of an image. When you experiment with the ISO, you can get great pictures which are exposed perfectly. ISO, basically takes care of the lighting aspect of your camera. Once you master how to correctly set the ISO, the result will be greatly improved.
When using a fast shutter speed, you must use a large aperture and high ISO to compensate for the little amount of light coming through the lens, in order to get the correct exposure. A fast shutter speed can be used in situations where you want to freeze the subject in its place, for example a bird flying or a football player. Hence, a fast shutter speed is often used for nature and sports photography.
A helpful table on which ISO to use when:
| Low ISO (50-400) | High ISO (800-3200) |
| Bright light | Sports |
| Landscapes | Dim light |
| Shooting on a Tripod | Concerts and plays |
| Making large prints | Indoors |
| Museums |
Below is a chart on how each of these factors work:
