A passionate photographer with years of experience in the field, Mark Decker enjoys the opportunity to capture the real world with a photograph. During his early years behind the camera, Decker learned about the fundamentals of camerawork, including the three pillars: shutter speed, ISO, and aperture. In the field of optics, aperture refers to a hole through which light travels. In photography, aperture settings determine the focus of the photograph.
Most cameras contain a structure called a diaphragm, which serves as an aperture stop and controls the aperture. The diaphragm functions much in the same way as the iris of the human eye, which expands and contracts based on the amount of available light and the desired depth. When a photographer such as Mark Decker reduces the size of the aperture, he increases the depth of field, defined as the extent to which objects of a certain depth appear to be in focus. A smaller aperture, typically indicated by a larger number, places objects situated a greater distance from the camera in focus. Larger apertures, on the other hand, keep only closer objects in focus while blurring objects in the background.
According to Mark Decker, while many photographers prefer adjusting the aperture on their own to achieve the desired focus effect, most single-lens reflex (SLR) cameras feature an automatic aperture control. With automatic aperture control, photographers can view and meter a subject at the maximum aperture. When it comes time to take the photograph, the camera reduces the lens to the working aperture during exposure and restores maximum aperture settings after the completion of the photograph. Many cameras also automate the shutter speed process, which plays an important role alongside aperture in determining how much light strikes the film or light sensor during exposure.
