Optics formula sheet

34 rows · 8 sections · PhysRef · sample of the first 6 rows

Optics formula sheet. Every optics equation in PhysRef on one sheet — 34 formulas across 8 topics, each with its equation set in real maths, a symbol key and the SI unit of every symbol.
Quantity	Equation	Symbols	SI units
Reflection
Law of Reflection	$\theta_i = \theta_r$	\theta_i = angle of incidence · \theta_r = angle of reflection	\theta_i: ° · \theta_r: °
Mirror Equation	$\frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i}$	f = focal length · d_o = object distance · d_i = image distance	f: m · d_o: m · d_i: m
Mirror Magnification	$M = -\frac{d_i}{d_o} = \frac{h_i}{h_o}$	M = magnification · d_i = image distance · d_o = object distance · h_i = image height · h_o = object height	M: dimensionless · d_i: m · d_o: m · h_i: m · h_o: m
Focal Length and Radius	$f = \frac{R}{2}$	f = focal length · R = radius of curvature	f: m · R: m
Fresnel Reflection (Normal Incidence)	$r = \frac{n_1 - n_2}{n_1 + n_2}, \quad R = r^2$	r = amplitude reflection coefficient · R = reflectance (intensity) · n_1 = refractive index of incident medium · n_2 = refractive index of transmitted medium	r: dimensionless · R: dimensionless · n_1: dimensionless · n_2: dimensionless
Spherical Mirror Focal Length	$\frac{1}{f} = \frac{2}{R}$	f = focal length · R = radius of curvature	f: m · R: m

Built from the 34 optics entries in the PhysRef reference, grouped by the topics that category page uses. Every equation here is free to read on its own page at /formulas.

Every row on this sheet is also free on its own page — browse the Optics formulas. Premium pays for the sheet, not the physics.