Blog about Digital Cameras
[19/07/2010] Role Played By Aperture in Digital Photography
Aperture is one of the three crucial elements of the exposure triangle and is considered the creative aspect of the digital camera photography; aperture is simply defined as the size of the opening in the lens of the camera while the picture is being taken.
In a digital camera it is the aperture which determines the amount of light while taking a picture, and that quantity of that light is directly proportional to the size of the hole that opens when the shutter release button is pressed, meaning the bigger the hole the more is the light and vice versa. Hence, it is imperative for the photographer to be aware of the ways in which the size of the hole can be regulated by adjusting the aperture so as to be able to take picture perfect photographs.
The unit, which is used for the measurement of aperture is referred to as f-stop and this is used in the technical jargon related to the field as being the f-number. F-stop is expressed as f/2, f/4, f/7.6, f/16, and f/22 and so on and every time the photographer moves to a higher f-stop he halves the size of opening in the lens while adjustment in the other direction brings about an increase in the same. However, as a knowledgeable photographer would be aware of, it is not only the aperture which determines the amount of light, but the shutter speed as well and therefore adjustment in one needs to be accompanied by an adjustment in the other as well.
One of the most noticeable effects of a modification of the aperture setting is its impact upon the depth of field (DOF), which refers to the amount of the shot that will remain in focus. A photograph might have a large depth of field (as the photo above) or a shallow depth of field and while the former implies that most of the scene would serve as the subject of focus, the latter implicates that only a small part of the scene would remain in focus and the rest would be treated as the background.
The relationship between the size of the aperture and the DOF is also inversely proportional like it is between the aperture and its f-stop value. Therefore, a large aperture which bears a smaller f-stop number will provide the photographer with a shallow depth of field while a smaller aperture bearing a large f-stop number will provide exactly the opposite effect.
Aperture setting plays a different role in different styles of photography and some of the styles which entail large aperture settings in order to acquire shallow depth of field are portrait photography and macro photography. The intention of the photographer while selecting large apertures and small f-stops in these styles is to capture the subject of the photograph completely in focus while the rest of the image appears as a blurred background. In contrast, while indulging in landscape photography, photographers opt for small aperture settings with large f-stop values so that the entire scene from the foreground to the horizon remains clearly focused upon in the photograph.
Amateur photographers often find the concept of aperture to be extremely confusing because it takes time for them to grasp the inverse relationship between aperture setting and the f-stop numbers. The first photograph below has been taken with an aperture of f/22 and the second one with f/2.8 and the difference is clearly visible.
The best way to gain mastery over this concept is to use the camera for performing various experiments by taking a series of shots of the same locale with different aperture settings. In this way, the photographer would be in a position to judge the impact as well as the usefulness of the aperture by comparing the different outcomes.
Other articles from this category:
[19/07/2010] Learning To Select Appropriate ISO Settings
[24/07/2010] Capturing Action Shots in Low Light Conditions
[28/07/2010] Utilizing an In-Camera Flash
