I took 3-4 hours worth of images at a select 4 points around Plymouth showing the shadow progression over time. This took along time obviously and I had to use chalk to mark where my tripod legs where at each location to get a similar framed shot. As I had to move about to the other locations 4 times in ever hour, I wasn‚Äôt able to get the shot exactly the same (different spots had different surface gradients and elevations etc) but they were good enough to convey the point in this project.
Once I had the images I went back to my mac and in Photoshop I de-saturated the images and increased the brightness and contrast slightly to make the shadows more prominent. The images had been taken on numerous sunny days so it did not take long at all to get the required results.