A slideshow is not merely a series of individual images. It is not a movie either – though in some cases video clips can form part of it. Nor can it be thought of as an amalgam of the two. A slideshow is an entity all of its own with its own conventions.
Now we can look at the images. How long should an individual image be on the screen? As a rule of thumb each picture should appear for between 8 and 15 seconds. (I can almost see the shock on your faces.) Any longer than that and the viewer's mind tends to wander. This means that the picture must be simple and to the point. Simple pictures? Yes! The purpose of most slideshows is to convey information not to show off photographic prowess. All images should be of a similar quality as any that stand out will give undue influence to what may be a minor point. That is not to say that a presentation should fall into mediocrity. Simple pictures generally have more impact. If what you have to say alongside the image takes longer than 8 to 15 seconds then you need to provide different views of the same subject.
Depending on how the presentation is going to be shown determines the aspect ratio of the image. Many current compact cameras allow a choice of ratios of 4:3, 3:2, or 16:9. Nearly all modern TVs use the widescreen 16:9 format and high-definiton TVs have just 1920x1080 pixels. Personally, when shooting pictures for slideshows I use the 16:9 aspect ratio but at the cameras highest definition. I resize them in image editing software, It may seem an extra step but it makes the reduced images incredibly sharp.
Switching to the 16:9 ratio for shooting has one big advantage: I can compose my image in the frame knowing that it will all fit on the screen. Using the highest resolution means that I can crop images if necessary.
Most of you images need to be in the horizontal format. Views that seem more natural in a upright configuration can often yield a good horizontal image too: you just need to use your photographic skills to find it. If the upright view really has to be used then switch the camera to a 4:3 aspect ratio. There are ways of using upright images and I will discuss that at a later time.
Remember that you will need a 'title' slide and an 'end' slide and the latter should also include credits. This can often be the same image with different texts overwritten. Using the same image brings things to a natural and recognisable conclusion.
Before you set out to take pictures make sure you have a 'shooting script'. If the script suggests you need a picture of a crowded bus station then it is no good arriving at 11am. More about writing scripts in the next instalment.