In particular, we will concern ourselves with images that already have the appropriate (e.g. creative commons) licenses, the correct size and resolution and, perhaps most importantly, suitable content.
When creating a presentation, the author needs to select pictures that have the ideal composition for maximum impact. What is photographic composition? Quite simply, the pleasing collection and organization of subjects within the picture area. There are ten criteria you can use when judging the success of picture composition.
- Balance: weighting the different parts of the picture, using the main and secondary elements equally; not to be confused with negative space or symmetry.
- Framing: using items in the background or the foreground to enhance the centre of interest of the main subject.
- Focus: throwing the background out of focus to make the main subject in the foreground stand out. Blurring and panning are used for the same effect.
- Geometric Shape: using the shape characteristics of the main subject to create a strong focal point.
- (Leading) Lines: actual lines or shapes that guide the eye and draw the viewer’s attention to the main point of interest.
- Mergers: avoiding the merger of the main subject with elements in the background or the foreground.
- Negative Space: placing the main subject off-centre while leaving the rest of the picture area around it empty intentionally; (positive space is the area occupied by the main subject).
- Pattern and Repetition: filling the frame with repeated objects that create a powerful visual impact.
- Rule of thirds: the placement of the subject off-centre along x or y axes that divide the picture in three thirds horizontally or vertically (as in tic-tac-toe).
- Simplicity: uncomplicated backgrounds that do not steal the attention from the main subject.
Not all will apply to any particular picture. Each one can be used to achieve a specific effect. Regardless of how stunning, impressive or spectacular this is, the ultimate guiding principle for the presentation author should be: how does it tie in with my intention?
More specifically, the picture will be used for any of the following reasons: for maximum visual and emotional impact, as a background to complement text, to explain or clarify a point.
For example framing can have a strong visual impact as in the picture below, especially if it is used on its own and covering the full slide area.
A picture showing an intriguing pattern, like the one that follows, can be used as the background for text provided the colours of the patterns are neutral enough or in subtle shades of gray.
A picture using negative space, as in the example below, can complement text quite effectively provided it relates to the content of the presentation or the meaning of the point being made.
The picture below, using the rule of thirds, can be used to illustrate the notion of leisure activities.
In conclusion, selecting the right picture to include in a presentation requires an understanding of picture composition, much more so if you intend to take your own pictures. In any case make the composition work for you rather than the other way round.