angular magnification

Angular magnification is a concept in optics that describes how much larger an image appears compared to the object itself when viewed through an optical instrument. It is specifically defined as the ratio of the angle subtended by the image at the eye to the angle subtended by the object at the eye when viewed directly.12

This type of magnification is crucial for instruments like magnifiers and binoculars, as it relates to the apparent size of an object from a specific viewpoint within the instrument. While there's no theoretical limit to magnification, practical limits are imposed by an optical system's ability to distinguish fine details, known as its resolving power.2