Design & colour
Light distance & falloff
Compare ideal point-source illumination at two distances.
A clear answer. Here’s how.
For a point source in free space, illumination ratio=(original distance/new distance)². Reports the remaining light percentage, light change in stops and compensating exposure multiplier. Extended sources, near-field softboxes, reflections, atmosphere and beam shaping do not necessarily follow this ideal model.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Original source-to-subject distance
- 1
- New source-to-subject distance in the same unit
- 2
Example result
- Remaining illumination
- 25%
- Light change
- -2 stops
- Compensating exposure multiplier
- 4