Optics & Waves
Intermediate

Thin Lens Equation

Relates focal length to object and image distances.

Formula

1f=1do+1di\frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i}

Variables

fFocal length
d_oObject distance
d_iImage distance

Did You Know?

The thin-lens equation lets opticians grind the exact lens needed to bring your world back into focus.

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