| Optical quantities | |
|---|---|
| Name | Symbol |
| Wavelength | λ |
| Illuminance | E |
| Period of oscillation | T |
| Refractive index (refraction coefficient) | n |
| Luminous flux | Ф |
| Aperture ratio of a lens | f |
| Luminous intensity | I |
| Speed of light | c |
| Linear magnification | β |
| Magnification of an eyepiece, microscope or magnifying glass | Г |
| Angle of reflection (or refraction) of a ray | ε` |
| Angle of incidence of a ray | ε |
| Focal length | F |
| Frequency of oscillations | ν, f |
| Radiant energy | Q, W |
| Luminous energy | Q |