Magnification of thin lenses
The magnification can be determined by considering the two red triangles in the image above. The magnification is, $$m= \frac{y_i}{y_o}=\frac{x_i}{x_o}.$$Using the thin lens formula, $\frac{-1}{x_o}+\frac{1}{x_i}= \frac{1}{f}$, the magnification can also be expressed as, $$m= \frac{f}{x_o+f}.$$ |