Image distance: object 50 cm from a 20 cm lens

Answer: image distance = 33.333 cm (magnification -0.667 ×).

What we know

  • Focal length: 20 cm
  • Object distance: 50 cm

Step by step

Given
Focal length = 20 cm, Object distance = 50 cm
Formula
1/f = 1/dₒ + 1/dᵢ
Result
Image distance = 33.333 cm

All results

Image distance33.333 cm
Magnification-0.667 ×

Open the lens equation calculator with these numbers → and change any of them.

The physics

The thin lens equation links three distances: focal length (the lens's strength), object distance, and where the sharp image forms.