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Measuring magnification
Dear Green,

Subject: The Power of a lens.

What you show here are "plus" lenses. The best term to use is "Diopters" to describe them.
The "power" is calculated once you know the diopter value of the lens.

If you wish to personally verify the "diopter power" of the lens -- do this.

Take the lens outside in sun light.

Hold the lens above a paper.

Move the lens up or down until the Sun is focused on the paper (smallest image).

Measure the distance between paper an lens.

For example

If the image forms at 20 inches, the power in diopters is 40/20
or 2 diopters.

In cm this would be 50 cm, and the calculation would be 1/0.5 = 2 diopters.

If the image formed at 1 meter (a weak lens), then it would be 1 / 1 = 1 diopter.

The lenses you presented would be in this range.



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Messages In This Thread
Measuring magnification - by hellogreen - 12-08-2008, 11:55 PM
Re: Measuring magnification - by otis - 12-09-2008, 08:27 PM