The Exposure Triangle

1. The Exposure Triangle Exposure is the combination of three factors. The Aperture size, Shutter speed and ISO setting. The combination of these three elements result in a photographs exposure value (EV). What is important to remember is that a change in any one of these elements will cause a predictable impact on the other (i.e. by changing the Aperture, you change depth of field; by changing ISO rating, you change the amount of light required to obtain an image, and by changing the Shutter Speed, you effect how motion is captured). You will never be able to independently control each of these elements, they are all connected as so will affect the final photograph.

5. Panning A clever trick called panning lets you combine a motion blurred background with an object in front which appears to be in focus. This is good for making an object or person appear to be in motion.

7. Scene Modes SLR cameras also come with some preset modes which are good for specific situations. Green Square – Full Auto Portrait Landscape Macro Mode – Flower icon for extreme close up shots Sports Mode – Fast moving action Night Portrait – Low light portraits Movie Mode – Newer SLR camera have HD video recording capability

8. White Balance Depending on what kind of source, light has different temperatures and will affect the hue (colour) of the photograph if incorrectly set.

9. White Balance The white balance can be set manually on a camera or set to auto If an incorrect setting is used you will notice that the image will have an unnatural hue of colour as shown in the images to the right. This photograph was taken under an Incandescent (tungsten) light. Once the auto white balance was set to this type of lighting it is clear from the results that the bottom right image is the most natural. The Auto white balance has also produced a good image however auto mode is not always reliable.

10. Setting Your White Balance Your camera will either have a white balance button or it will have an option through the system menu. You will be presented with a screen like the one opposite and from here you can pick the setting which best matches your lighting conditions.

11. Auto Exposure Bracketing (AEB) Sometimes we don’t have time to fiddle around with Shutter and Aperture to get a shot perfectly exposed the first time. Sometimes the lighting is difficult to read. In these situations we can use Auto Exposure Bracketing to help us. Auto bracketing takes 3 – 5 shots all with different exposure settings increasing the chance of getting a well exposed image.

12. A range of bracketed images

13. HDR – High Dynamic Range Photographers sometimes use bracketed photographs to produce an HDR image. An HDR image is one which show a greater range of light and dark in a photograph than is possible through traditional film or digital cameras. HDR images are a combination of photographs which show a varied range of exposures. This combination can produce an image which more closely replicates the range of exposure a human eye can see.

14. Due to the effect of HDR images they can often be seen to blur the line between reality and illusion.