Image Scale Per Pixel Back | Up | Next

Calculating the image scale per pixel is useful for high-resolution planetary or double star imaging where it is important to match the resolution of the telescope to the resolution of the sensor.

Formula 12    Image Scale Per Pixel

P = (8 * S) / (FL)

Where:

  • P is the image scale per pixel in arcseconds
  • S is the size of the pixel in microns
  • FL is the focal length in inches

Example: Calculate the image scale per pixel for a Canon 20D camera with 6.4 micron pixels when used on a 5 inch f/8 telescope with 40 inches of focal length.

P = (8 * S) / (FL)
P = (8 * 6.4) / (40)
P= (51.2) / (40)
P = 1.28 arcseconds per pixel

Each pixel in a Canon 20D camera when used on a 5 inch f/8 telescope will cover 1.28 arcseconds of the sky.



















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