Composition: Part IV Isolating the Subject Author: Wendy Folse First published on: July 1, 2001 Isolating the Subject One of the most important points to consider in composition is isolating the subject so that it becomes apparent to the viewer what the photographer is trying to show. There are many ways to isolate the subject and in this article, we will cover three of them, framing the subject, selective focus, and depth of field. The main purpose for isolating the subject is to make it stand out from the background and to direct the viewer's eye to the center of attention, not necessarily the center of the photo. In the portrait of the young girl, the eyes are the center of focus and the hat, leaves, and even her hair help to frame her face which is the center of attention. Framing the subject The first choice in deciding how to frame the subject in the viewfinder is to decide whether you want a horizontal or vertical composition. In a previous article we discussed the merits of both. The choice is up to the photographer, but ultimately the frame choice should compliment the subject. A skyline looks best in horizontal, while a single tall building looks best in a vertical. The next consideration is where we get a little more creative and where we start to make choices, that brings our photography to a new level. This step requires us to think a little and to scout around for things that we can use to frame our subject in order to direct the viewers eye towards the main point of interest. Framing devices help to keep the subject contained within the photo. A photographer's choice is limited only by his imagination and skill when choosing a framing element. Maybe it is a palm tree in the foreground that gracefully wraps around the beach in the distance. Perhaps, it is the outline of a window that the viewer looks through to the fields beyond. Nothing says, "we're at a football game" like a shot of the crowd framed by the upright goal post. Or how about the often overused classic of a bride looking at her reflection in a mirror. This is a technique called a frame within a frame.
Even a bare white wall can frame the subject by isolating it when the only element surrounding the subject is the white wall. This is the same concept as a photographer using a backdrop. The purpose for the backdrop is to in a way frame the subject with a continuous pattern, color, or tone. Patterns are often used as framing devices to help contain the subject within the photo. Look around you and see what elements are present that may lend themselves to this technique. In the picture here, the iron mesh of the gates serve as a frame. Depth of field can also be used as a framing device to isolate the subject. Using a very shallow depth of field can blur the background creating a frame that surrounds the subject. Another consideration is the eventual framing of the photo itself. Be careful not to place parts of the composition so close to the edge of the viewfinder that they will be cutoff either during printing or when matting and framing. Selective focus This technique relies on the creative use of depth of field and a large aperture to direct the emphasis on the subject by deliberately placing surrounding elements out of focus. Sometimes the foreground maybe placed out of focus in order to frame a distant subject. Often the background will be placed out of focus in order to emphasize a foreground element. The idea is to use what is in‐focus and what is out of focus as a tool for isolating the subject. Again with this technique as with others, it is limited only by the photographer's imagination and creativity. In order to use selective focus effectively you must first learn to understand depth of field and how to control it. In a future article we will be covering depth of field to a greater extent. For now, it helps to gain a basis for what it is and what it does. Depth of Field The term is used to describe the amount of distance in a photograph that is in sharp focus. Sometimes it is easier to think of depth of field as an imaginary plane that crosses the "field" of the photo from front to back. The further back or depth of the plane, than the more that will be in focus. The size of the aperture controls the depth of field. At very small apertures such as f/22, the plane covers all subjects
and all are in sharp focus. When we use a very large aperture such as f/2, then there is a very limited depth of field and only the exact focusing point maybe sharp while everything else is blurry. When working with very large apertures it becomes critical to pick out a focal point and center the focusing on this spot in the viewfinder. As three dimensional objects do not occupy one plane, the photographer must keep in mind which part of the object is critical and adjust the focus on this point. This is where a depth of field preview button on an slr comes in handy. If your camera doesn't have one then your task is to think about the amount of focus necessary to represent the object according to your chosen theme. What are you trying to show and how critical is it. Remember that what you see is not necessarily what you get when working with larger apertures. The amount of blur may not be apparent in the viewfinder even with a depth of field preview. The distance at which you focus on an object also controls the amount of depth of field. The farther away you focus, the larger the depth of field. The closer in you focus, the shallower the depth of field. There is a rule of thumb that says that from the focal point you have about one‐third of the distance in front of the focal point and two‐thirds of the distance behind the focal point. When shooting landscapes at small apertures this factor is not critical because everything will be reasonably sharp. However, when working with smaller objects at closer distances and using larger apertures, this does become very critical. It helps to remember that a photograph is a one‐dimensional representation of a three‐dimensional scene. For example, say that you wish to take a close‐up portrait of a person and you want to blur the background. After you work out the correct lighting, you decide you need a relatively larger aperture in order to blur the background but you don't want the face to be blurry either. What do you do and where do you place the focus point in order to assure that the face is in sharp focus? Think of the human head as being divided into three planes, from front to back. The nose is in the first plane, the eyes fall in the second plane and the ears and back of head are in the third plane. If you chose to place the focal point on the nose, one third of the distance in front of the nose would be in focus and two thirds of the distance behind the nose would also be in focus. That should mean that the entire head would be in focus. Maybe, maybe not depending on how large an aperture you are using.
By choosing the nose as the front plane you are accenting it and moving the other planes backwards. Most people would not find this pleasing. So where else could you place the focal point? The desired place to focus on a human face is the eyes. The reason is the same as mentioned above. The human head is divided into three planes with the eyes being located in the second third. This means that if you focus on the eyes, one third in front (the nose), and two thirds behind (the ears and then hair) will be in focus. The eyes are the critical points that must remain sharp. The focus point is the point at which maximum sharpness is too be obtained, the degree of sharpness begins to fade away from this point with the degree of fall‐off depending on the size of the aperture. The smaller the aperture, the greater the depth of field. The larger the aperture, the smaller the depth of field. Here is another example, suppose you are taking photo of a large group of people and you want the background to fade away slightly. Because of the light, you are using a larger aperture. Now how do you insure that every row will be in sharp focus? Do you focus on the front row? Or on the back row? Or which row? Go back to the rule of thirds, remembering that you have about one‐third in front of the focal point and two‐thirds behind. View the group as a block occupying space and distance. Mentally divide the block into thirds and place your focus accordingly. Depending on how large an aperture you are working with, the group should be relatively in focus and the background should be slightly blurred. It is always a tradeoff. What is important and what isn't. In this situation a professional will start adjusting light, changing lens, altering distances and repositioning himself all in an effort to achieve the precise results he wants. He will choose the best possible aperture under the conditions. For most amateur and point and shoot photographers this may not be possible, so keep the above rule in mind and you can begin to take great pictures with the available equipment. The article on depth of field goes into greater detail, but for now we are just covering it as it pertains to composition. What are we taking a picture of and how do we want it to look. Distracting Elements This is a point that should be stressed often. Take the time to look around the viewfinder. The few extra seconds of attention to details will make a difference in the quality of your pictures.