A dynameter is an instrument that measures the

magnification Magnification is the process of enlarging the apparent size, not physical size, of something. This enlargement is quantified by a size ratio called optical magnification. When this number is less than one, it refers to a reduction in size, so ...

of a

telescope A telescope is a device used to observe distant objects by their emission, Absorption (electromagnetic radiation), absorption, or Reflection (physics), reflection of electromagnetic radiation. Originally, it was an optical instrument using len ...

. It is usually a double-image micrometer 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