The most common slide element used after text is a graphic, usually a photograph or a vector drawing. The old saying goes, "A picture is worth a thousand words" and it is true. Just make sure that the thousand words being spoken by the graphics you use on your presentation slides are words that will increase the impact of your message, not detract from it. Here are some areas to keep in mind when choosing graphics to use on your presentation slides.
Graphics Should Add to the Point
The real reason for using a graphic is to add some flavor to the text that is on the slide. It gives the audience visual variety, which keeps their attention raised. A good choice of graphic can make a point come alive in the audience’s mind. A poor choice of graphic will leave the audience wondering what the point really is since the graphic is inconsistent with the message. I once saw a presentation where a picture of the Eiffel Tower in Paris, France was on a slide. It was a beautiful picture, but it had absolutely nothing to do with what was being spoken. Make sure you carefully select each graphic to match the point you are making on that particular slide. I spend far longer choosing a graphic than I do typing in the text.
With the wide availability of photos, using clip art is seen as outdated and will cause the audience to think less of you as a presenter. If you don’t want to use photographs, select vector drawings. You can use vector icons as I describe in this article (also contains a method to convert vector files into a format PowerPoint can use) or select vector drawings from a source like istockphoto.com. These drawings are much higher quality than the amateur looking clip art that audiences have come to dislike and they can be scaled without distortion.
The most common graphic used on presentation slides is a photograph. This can be a digital photo you have taken, a print you have scanned, a photo you have downloaded, or a photo supplied in your presentation software package. Select photos that others are not commonly using. Pay attention to colors of the photo to make sure they contrast well with your slide background so they can be seen. With photographs, you also need to be aware of the emotional impact that a photo has. Unlike clip art, photographs evoke a direct emotional response when shown, they bypass the logic center of our brains. The emotional response tends to be stronger for photos of people than it does for photos of inanimate objects, although there are exceptions. Be careful in using photos that may evoke strong positive or negative emotional responses to make sure that you want that emotion to be in the audience at that point in your presentation.
When you are selecting or taking a digital photograph, one concern is what resolution do I need? If the photo is only being used on a presentation slide, you do not need a high resolution image, a 1024x768 image is fine. If the photo will also be used in a print publication, you will need a much higher resolution and it is best to ask the print production staff what resolution they prefer. If you have a high resolution photo that you want to use on your presentation slide, try to have the resolution reduced in a graphic program before you insert the image. A high resolution image takes a lot of disk space to store and inserting a large image file in your presentation will make your presentation file very large and run more slowly.
Modifying Graphic Images
Once you have your graphic image in your presentation slide, you can make some changes to the image that will make it even more effective. Here are some of the most common changes.
Size – The size of the graphic should be big enough to be seen easily. To change the size, you can usually just drag an expansion handle at the corner of the image once it has been selected. I suggest holding the Shift key down while using the corner handle to size an image because it keeps the same aspect ratio (the ratio of width to height) and does not distort the image.
Cropping – If the image you want is a portion of the total image, you can crop out the areas you do not want after it is inserted on your slide. This function is usually found in the Properties section of the graphic element. It is a good idea to check the size of the image first before setting the cropping distances from each edge so that you can get closer to the image you want within just a few attempts.
Brightness – When using photographs, the brightness of the photo has a large impact on how well it will look when displayed. This effect is magnified further when the image is displayed on a screen through a data projector in a lighted room. I have found that in many cases I have to make the photo brighter on my screen in order to get a good image through a data projector. The brightness setting is found in the graphic element Properties usually. Check your photos using the data projector you will use and the room lighting if possible. If checking before the presentation is not possible, learn how to set the brightness and be prepared to test the photos and change it if necessary when you set up for your presentation.
If you select your images carefully, the pictures will add "a thousand words" to the message you are delivering and you will increase your impact on the audience.
To learn more about finding and using photos on your PowerPoint slides, check out my Implementation Guide.