Photoshop Exercise Files

The material offered for download in this section of the site is copyright. You may not publish any of this material in any form, reproduce it on public Web sites, or pass it off as your own. It is supplied for use in private and institutional study only.

The files supplied here are mainly Photoshop (PSD) files, and some are quite large. The photographs are not necessarily at their original resolution – in many cases we have downsampled to produce more manageable file sizes, where this does not interfere with the purpose of the exercise.

These exercises are supplementary to the "Try This" exercises in Digital Media Tools, but relate directly to sections in the Photoshop chapter. Please choose a topic from the list below to see the range of exercises for that section:

• Resolution and resampling
• Making and using selections
• Adjustments and retouching
• Effects and filters
• Erasing and fills
• Animation

Resolution and Resampling

Download the photograph of cactuses [PSD:6.6MB]

Download the photograph and try changing the resolution without resampling, to see what effect this has on the display of the image. Change the resolution back to 72 dpi and experiment with reducing the size of this large image without changing the resolution again. (Refer to page 85.) Blow up the image on screen (View>Zoom In) to see the effects of the downsampling in detail. Assess how far you can downsample without a substantial loss of quality, but think about the size at which you might want to display the image.

Download the photograph of the lighthouse [JPEG:32kB]

Download this small JPEG file and experiment with enlarging it. Try each of the different interpolation methods and observe any differences. Try enlarging the image by several hundred percent, and then repeating this process again. What happens to the image and why? Can you see a sort of halo round the lighthouse and perhaps in other areas? What do you think might be the cause of this?