Distance Perspective Projection Converter
This calculator estimates the angular size of an object as seen from a given distance, or conversely, calculates the distance required to achieve a specific angular size. It’s widely used in astronomy, photography, optics, and vision science to simulate how large an object appears to the observer depending on its real size and distance.
Angular Size and Distance Calculator
Angular Size Formula
Where:
- $$L$$ = distance to the object
- $$D$$ = actual (linear) size of the object
- $$\alpha$$ = angular size (in radians or degrees)
This equation rearranges the angular size formula to find the distance needed to view an object of size D under angle \alpha.
Perspective projection is fundamental in understanding how objects appear smaller at a distance. This formula is crucial in fields like astronomy (e.g., how large the Moon appears), photography (field of view), or architecture (viewing angles). For example, given a building height of 50 meters and a viewing distance of 100 meters, the formula shows how wide it appears in your field of view. It supports unit conversions and calculations for any known two variables out of the three.
I know what perspective is, but I don’t know how to use this calculator. I’ll have to learn the math in order to use the calculator. . . and to me that sort of defeats having a calculator. We live in the era of spreadsheets, after all.