Simple Magnifier

The simple magnifier achieves angular magnification by permitting the placement of the object closer to the eye than the eye could normally focus. The standard close focus distance is taken as 25 cm, and the angular magnification is:

Magnification:Transverse &Angular

The linear magnification or transverse magnification is the ratio of the image size to the object size. If the image and object are in the same medium it is just the negative of the image distance divided by the object distance, but if the media are different it can be variously expressed as

The angular magnification of an instrument is the ratio of the angle subtended at the eye when using the instrument divided by the angular size without the instrument. An important example is the simple magnifier. The angular magnification of any optical system can be obtained from the system matrix for the system.