Information

EXPOSURE

Exposure is the amount of light that reaches the camera's sensor (or film). If we don't get enough light we end up with a photo which is dark (underexposed). Too much light and our photo comes out bright (overexposed). A perfect exposure captures the right amount of light without losing detail in the highlights or shadows. So how do we control exposure? It all comes down to a combination of two basic camera settings - aperture diameter and shutter speed. Let's examine each in turn.

SHUTTER SPEED

Shutter speed is simply a measure of how long the camera's shutter is open for. It typically ranges from anywhere around 1/1000th of a second (a fast shutter speed or short exposure time) to several seconds (a slow shutter speed or long exposure time). Choose a shutter speed that allows you to capture enough light without blurring the subject. Obviously, the longer the shutter is open for, the more light reaches the camera's sensor, and vice versa.

APERTURE

Inside every camera lens is an opening called the aperture which works in exactly the same way as the pupil in a human eye. The aperture changes diameter from a wide aperture which lets in lots of light, to a narrow aperture which lets in less light. Aperture diameter is measured by an "f-number". Typical values are f2.0, 2.8, 4.0, 5.6, 8.0, 11, 16, 22, 32. Somewhat confusingly, a smaller f-number represents a wider aperture and therefore more light, and a higher f-number is a narrower aperture and less light. (For the mathematically minded this is because f-number = focal length / aperture diameter). An important thing to grasp is that these f-numbers are spaced one "f-stop" apart. By moving one f-stop you either double or halve the amount of light the aperture admits, meaning you need to either halve or double the shutter speed to keep a constant exposure.

Composition

Simply put, composing an image means arranging elements within it in a way that suits the core idea or goal of your work best. Arranging elements can be done by actually moving the objects or subjects. A good example for this case is portrait or still life photography. Street photography involves anticipation, since the photographer doesn’t usually have the choice of moving his subjects himself, but has to wait for them to take the most suitable position within the frame. Another way of arranging elements is by changing your own position. Such a way is appropriate in circumstances that do not allow the photographer to physically move anything, like landscape photography.

Composition is a way of guiding the viewer’s eye towards the most important elements of your work, sometimes – in a very specific order. A good composition can help make a masterpiece even out of the dullest objects and subjects in the plainest of environments. On the other hand, a bad composition can ruin a photograph completely, despite how interesting the subject may be. A poorly judged composition is also not something you can usually fix in post-processing, unlike simple and common exposure or white balance errors. Cropping can sometimes save an image, but only when tighter framing and removal of certain portions of the image is the correct solution. That is why giving your choice of composition plenty of thought before capturing an image is a step of utmost importance.

Focal length, aperture, angle at which you choose to position your camera relative to your subject also greatly affects composition. For example, choosing a wider aperture will blur the background and foreground, effectively lessening the importance of objects placed in there. It will also more often than not result in more noticeable corner shading (vignetting), which will help keep viewer’s eye inside the frame for longer. On the other hand, closing down the aperture will bring more objects into focus which, in turn, may result in better image balance. How so? Well, “sharper”, more in-focus objects may attract more attention than a blurry shape, but not always (see image sample below). An experienced photographer will use all the available means to achieve the desired result. It is worth noting that de-focusing objects in the foreground or background does not negate their contribution to overall composition of the image. Simple shapes, tones, shadows, highlights, colors are all strong elements of composition.

Rule of thirds 

The basic principle behind the rule of thirds is to imagine breaking an image down into thirds (both horizontally and vertically) so that you have 9 parts. As follows.

The rule of thirds 1

As you’re taking an image you would have done this in your mind through your viewfinder or in the LCD display that you use to frame your shot. With this grid in mind the ‘rule of thirds’ now identifies four important parts of the image that you should consider placing points of interest in as you frame your image. Not only this – but it also gives you four ‘lines’ that are also useful positions for elements in your photo.

The rule of thirds 2

The theory is that if you place points of interest in the intersections or along the lines that your photo becomes more balanced and will enable a viewer of the image to interact with it more naturally. Studies have shown that when viewing images that people’s eyes usually go to one of the intersection points most naturally rather than the center of the shot – using the rule of thirds works with this natural way of viewing an image rather than working against it.

Depth of Field 

Depth of Field is the zone of acceptable sharpness within a photo that will appear in focus. In every picture there is a certain area of your image in front of, and behind the subject that will appear in focus. Others may have a very large zone of focus which is called deep depth of field. Three main factors that will affect how you control the depth of field of your images are: aperture (f-stop), distance from the subject to the camera, and focal length of the lens on your camera. 

Balance

Balance is a compositional technique in photography that juxtaposes images within a frame so that the objects are of equal visual weight. When different parts of a photo command your attention equally, perfect balance is achieved. In photography, there are two main techniques of balance you should be aware of: formal and informal. We’ll discuss the difference between each and how they can affect your photo.

Knowing how to effectively balance objects within a photo is a skill that all serious photographers must learn. The problem with improperly balanced photographs is that they are less appealing to look at and can instantly turn off a viewer.

Balancing elements in photography becomes important when you frame your shots. If you think back to the chapter on the rule of thirds, you’ll remember that we explained how placing the main subject of your photo off center can create a more dynamic photo. That’s because asymmetry makes a photo more appealing to a viewer because it causes visual tension.

The only problem with the rule of thirds is that it can also leave a wide open empty space in a photo which may make the scene feel empty. In some instances this may work very well for your image, but if it doesn’t you should try to balance the visual weight of your subject by including other objects to fill the empty space.