Physics

Thin Lens (image distance)

Image distance from focal length and object distance.

Formula

Formula
1f = 1do + 1di

Variables

SymbolDefinitionType & rangeUnitsRole
f focal length real number (ℝ) input
dₒ object distance computed result result

Try it yourself

Interactive calculator
Result

Worked examples

Example 1
Givenfocal length f = 10, object dist dₒ = 30
Result15
Example 2
Givenfocal length f = 5, object dist dₒ = 15
Result7.5