Click to open an Excel worksheet and use Part 1. Image Sizes to follow the instructions in this section.

Part 1 on the Excel worksheet "Pixels & Images Calculator" calculates the total number of pixels in an image and its aspect ratio when you enter the image's width and height in pixels. The numbers in the descriptions that follow refer to row numbers on the worksheet.

4. Aspect ratio is calculated by dividing the image's width by its height.

Exercises

Open the PixelCalc.xls worksheet by clicking the Excel button in this section and enter numbers in the green cells to explore the following questions.

1. Enter the width and height of your own images to find the total number of pixels they contain and their aspect ratio. You can find image sizes in your camera's user guide. There may be more than one resolution, and if so, try them all. When the resolution changes, does the aspect ratio also change?

2. If a digital camera recorded the following image sizes, how many pixels are there in each image size? What is the aspect ratio for each?

. 2,400 x 1,800

. 1280 x 960

. 640 x 480

3. Here are some rectangles commonly found in photography. Calculate the aspect ratio of each.