Subject Width in Frame
A distant-subject approximation estimates the horizontal scene width captured at a given distance.
Subject Width in Frame
Optics · 3 inputs
How to use this calculator
- Enter subject distance in m.
- Enter sensor width in mm.
- Enter focal length in mm.
- Select Calculate and keep the output unit with the answer.
Before you use the answer
Keep capture settings, physical dimensions and delivery requirements in separate columns of the job notes. A mathematically equivalent setting may change motion blur, depth of field or noise. Check an actual frame before committing an entire session to a numerical estimate.
Close-focus work needs magnification and principal-plane information beyond this simple model.
Does it save my inputs?
No calculation history is stored by this website. The calculator works locally in your browser. See the privacy policy for hosting and contact details.
Why might a result be approximate?
Measurement uncertainty, ideal-model assumptions and floating-point rounding can all matter. Displaying more digits does not improve the original measurement.
Related calculations
Distance for Subject Width
Rearranging the angle-of-view geometry gives a starting camera distance for a desired framing width.
Open calculator ↗Hyperfocal Distance
Hyperfocal distance comes from a geometric sharpness criterion set by the circle of confusion.
Open calculator ↗Near Depth-of-Field Limit
The near depth-of-field boundary estimates where defocus reaches a chosen blur-circle tolerance.
Open calculator ↗