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How to Calculate Sensor Size

According to David Pogue, technology writer for "The New York Times," your digital camera's sensor is the "single factor that predicts the quality" of pictures taken with the camera. A larger sensor picks up more information more accurately, even if the pixel dimensions of a smaller sensor are identical. The problem is, most sensor sizes are given in length and width figures, and in millimeters, which makes them hard to compare. By calculating the diagonal of the sensor, you can make useful comparisons with other sensors.

Things You'll Need

Calculator
Manual for the camera with sensor specs

Instructions

- 1
  Divide the height of the sensor in millimeters by 25.4 to convert it to inches. For a height of 14 millimeters, that is .551 inches.
- 2
  Square the height of the sensor in inches (multiply it by itself). Squaring the figure from Step 1 yields .304 inches.
- 3
  Divide the width of the sensor by 25.4. A width of 21 millimeters converts to .827 inches.
- 4
  Square the width of the sensor in inches. Squaring the example from Step 3 gives .684 inches.
- 5
  Add the squares of the height and width of the sensor together. In this example, the result is .988 inches.
- 6
  Take the square root of the result from Step 5 to get the diagonal of the sensor in inches. In this case, it equals .994 inches.

Photography