Exposure is the most important component in photography. It is the amount of light that reaches the sensor of the camera and is measured using the term exposure values (EV) or stops. A photographer uses exposure to control what he wants to show in the photo. It is the opposite of a painting where a painter starts with a blank canvas and fills in the colour. A photographer, on the other hand, starts with all the colours and limits what is seen.

Three elements can control an exposure:
1. Aperture
2. Shutter
3. ISO

Learning them is crucial to your development of being a photographer. Once you have an understanding of this, you can utilise the full potential of your camera. In most cameras, you can usually select the following modes: P or Auto, A or Av for Aperture, S or Tv for Shutter and M for Manual. ISO is usually on a separate button.

Exposure Compensation and Metering

Today’s DSLR has an integrated light metre that will automatically measure the light hitting the sensor and determine the correct exposure setting. For this article, let’s keep it to Evaluative/Matrix depending on which camera you use. With this setting, your camera selects the lighting from the whole image and computes the best exposure needed for the picture. Most times, it does a good job but sometimes it misses the mark. When that happens, you turn to Exposure Compensation.

Your digital camera will likely have a button with a plus/minus icon. This function works when you are using either the Aperture or Shutter mode. If the image is too dark, while holding down the button, you turn your dial to increase by 1/3 stop. Take another picture to see the image appear brighter. Increasing it by another stop will make the image brighter. It works the opposite if you decrease the stop.

TRY

Set to Aperture mode, Matrix metering and Exposure Compensation to zero. Take a photo and check out the image exposure. Try different values in your EV and see what happens.

Lighting—using natural light

Just like buying a light bulb, natural light comes in many colour temperatures, which is measured in Kelvins (K). To produce a beautifully exposed image with true to life colours, you must learn to effectively use the white balance setting of your digital camera. There are many factors that can affect the white balance and the chances are that you have taken a photo that doesn’t quite look like the original colour. Most modern cameras have an Auto White Balance setting that does a good job at getting it right. However, there are times when you need to change from Auto to the correct White Balance setting.

The diagram (image 2 from top) is a guide on using the White Balance setting.

You can use White Balance creatively to change the colour tones to produce the desired effect. For example, in the first image from the top, you see the original colours of the sunset. If you change the white balance to a low Kelvin using the Fluorescent setting, the result can be seen in the last image.

Cloudy White Balance

Fluorescent White Balance