With images, it’s about focus

When is an image not an image? When it’s out of focus. The effective use of images in presentations is often bedevilled by presenters failing to obey simple rules, principally though ignorance. Some of the common mistakes are more obvious than others but limit the effectiveness of images (p2) in supporting the overall value (p3) of the presentation.

Use of a small, poor quality image stretched to fill a slide only degrades the quality of the viewed image as it becomes pixellated. Similarly, stretching an image to fit the lateral or vertical dimensions of a slide degrades the quality and dimension of the image.

A composition trick known as the “rule of thirds” works within an image directing the gaze to the intersection of the outer thirds of the image. Composition placing the point of interest of the image here will find the eyes of the audience immediately drawn to these points. In both the images below our eyes are drawn first to the face. In the upper image however the “view” of the subject leads us out of the image and the rest is redundant. In the second the view is drawn down, again towards the outer third.

Recognition of this visual signalling allows placement of text in the most effective position. We are drawn first to the eyes and then “what” the subject appears to be looking at.

With images, it’s all about focus.


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    How large an image file (minimum) is necessary for a slide? It is not always possible to tell on a laptop how it’s going to look on a projected image.

    1. ffolliet (Post author)

      Good question. As big as possible is the simple answer as that is effectively a marker for quality. most sites will advise you of the size of the image, if not right click and it should be there. Under Google Image search the pull down menu has options for Usage Rights (your first selection) and then Tools will allow you to search under Size- Large.

      A rough and ready guide is to set up the slide and then press “play” in your appropriate software. If there is ANY grainy or odd focus look to it on your laptop it will be poor on a big screen. Step back a bit and it should be more obvious.

      Go large, as the burger joint would encourage you!

      1. Christine

        Much appreciated!
        New motto: Go large or go home


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