Aperture, also known as f-stop, is one of the three main components of a camera’s exposure triangle, along with shutter speed and ISO. It is a measure of the size of the lens opening that allows light to pass through and reach the camera’s sensor. In a DSLR camera, the aperture is controlled by a diaphragm inside the lens.
The aperture is measured in f-stops, and the lower the f-stop number, the larger the aperture. For example, an f-stop of f/1.8 is a larger aperture than f/8. A larger aperture allows more light to pass through the lens, which can result in a brighter image and a shallower depth of field. A smaller aperture allows less light to pass through the lens, which can result in a darker image and a deeper depth of field.
The aperture also affects the bokeh (the blur effect of the out-of-focus areas of the image) of the image. A larger aperture (smaller f-stop number) will result in a shallow depth of field, making the subject of the image stand out more, and the background will be more blurred. A smaller aperture (larger f-stop number) will result in a deeper depth of field, making the image look more focused, and the background will be less blurred.
In conclusion, the aperture controls the amount of light that enters the camera, it’s measured in f-stop, and it affects the brightness and the depth of field of the image. It is one of the key elements for a photographer to control in order to achieve the desired effect in the image.