Photography & Imaging
Intermediate

Thin Lens Equation

Relates focal length to object and image distances.

Formula

1f=1u+1v\frac{1}{f} = \frac{1}{u} + \frac{1}{v}

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Variables

fFocal length
uObject distance
vImage distance

Example

f=50 mm, u=200 mm: v = 66.7 mm

Did You Know?

This one equation governs everything from a phone camera to the Hubble Space Telescope.

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