The definition of the aperture is a measure of how much the lens opens (lens opening) when we take a photo. When we press the shutter button, the hole in front of our camera sensor will open, it is the aperture setting that determines how large this hole is open. The larger the open hole, the more light that will enter is read by the sensor. Understanding these two concepts is necessary, so you will be able to learn the more advanced fields of photography, such as the wedding and boudoir photography.
Aperture or opening is expressed in units of f-stop. Often we read the term aperture 5.6, in a more formal photography language can be expressed as f / 5.6. As revealed above, the main function of the aperture is to control how big the hole is in front of the open sensor. The smaller the number of f-stops means the larger the hole is open (and the more volume of light enters) and vice versa, the larger the number of f-stops the smaller the open hole.
So in reality, the f / 2.8 aperture setting means a much larger opening than the f / 22 setting for example (you will often find the term fully open when you hear the photographer’s chat). So the width opening means the smaller the number f and the narrow opening means the greater the number f.
Understanding Depth of Field
The depth of field – DOF, is a measure of how far the focus field is in a photo. Wide Depth of Field (DOF) means that most photo objects (from the closest object from the camera to the farthest object) will look sharp and focused. While the narrow DOF (shallow) means only the object’s part at a certain point is sharp while the rest will be blurry / out of focus.
To get a wide DOF, use a small aperture setting, for example f-22 (the smaller the aperture the wider the focal distance). While to get a narrow DOF, use an aperture as large as possible, for example, f / 2.8.
This Depth of Field concept will be very useful especially in portrait photography and macro photography, but actually, all specialties will need it.