A dynameter is an instrument that measures the magnification of a

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observ ...

. It is usually a double-image

micrometer Micrometer can mean: * Micrometer (device), used for accurate measurements by means of a calibrated screw * American spelling of micrometre The micrometre ( international spelling as used by the International Bureau of Weights and Measures; ...

used to measure the diameter of the image of the object glass. The magnifying power is found by comparing the actual diameter of the glass with the measured diameter of the image of the glass.

References

Dictionary entry
for ''dynameter''.

archived fro

{{optics-stub Optical instruments Measuring instruments Astronomical imaging Telescope instruments