Depth of Field Far Limit Calculator

Thin lens farDOFlimitHs/[H−(s−f)], actual same units/fixed CoCmodel, finitebranchs−f<H. Infinity branch explicitly rejected not replaced finite value; near DOF is distinct.

Description

A thin-lens far depth-of-field limit depends on a separately established hyperfocal model and matched distance units.

A thin-lens far depth-of-field limit depends on a separately established hyperfocal model and matched distance units.^[1]

This tool calculates only the finite far-limit branch and rejects the infinity case.

When to use Depth of Field Far Limit Calculator

Use this tool to calculate only the finite far-limit branch and rejects the infinity case.

How to use Depth of Field Far Limit Calculator and how it works

Prepare actualHyperfocalDistance, actualFocusDistance, actualFocalLength, with the units, conventions and assumptions below.
Enter the required fields and run Depth of Field Far Limit Calculator.
Read result.value using the output definitions below.
Correct any rejected inputs and rerun; interpret the result within the stated model and its assumptions.

Input field	Meaning	Value type	Requirement
actualHyperfocalDistance	Actual Hyperfocal Distance. Use the units and matching context stated in the calculation below.	number	Required; strictly positive; finite; other constraints below
actualFocusDistance	Actual Focus Distance. Use the units and matching context stated in the calculation below.	number	Required; strictly positive; finite; other constraints below
actualFocalLength	Actual Focal Length. Use the units and matching context stated in the calculation below.	number	Required; strictly positive; finite; other constraints below

Supply positive hyperfocal distance H, focus distance s and focal length f in one length unit. Require s>=f and s-f<H, then return H*s/(H-(s-f)). An infinite or beyond-branch far limit is rejected instead of returned as infinity; the tool does not calculate H from aperture or circle of confusion.

farLimit=H*s/(H-(s-f))

Apply the input ordering, units and branch conditions stated above.

Output field	Meaning	Value type
result	Object containing the calculated or selected fields below.	object
result.value	Finite far-focus limit in the input length unit.	number

json

{
  "input": {
    "actualHyperfocalDistance": 4,
    "actualFocusDistance": 2,
    "actualFocalLength": 1
  },
  "output": {
    "result": {
      "value": 2.6666666666666665
    }
  }
}

Limitations and assumptions

The calculation uses the supplied observations and model inputs. It does not collect measurements, select a reference population or coefficient, or establish that the model applies to the actual case. The stated branch conditions and output units remain part of the result.

All fields require explicit values. Unexpected fields, wrong types, nonfinite numbers and sparse arrays are rejected. Alignment, bounds and supported-token rules are explained above; extremely large inputs or nonfinite results can also fail. Input errors differ from successful false comparisons, unavailable-domain flags and empty match lists.

Alternative or Complementary methods

Use Flash Sync Speed Calculator for a complementary operation: A nominal full-open mechanical flash-sync frequency depends on curtain travel and an independently required margin.

Use Flash Exposure Calculator for a complementary operation: A direct-flash guide-number estimate relates aperture, subject distance and the chosen ISO reference.

References

Depth of Field Far Limit Calculator — tool.io

Similar or alternative tools

Flash Sync Speed Calculator
A nominal full-open mechanical flash-sync frequency depends on curtain travel and an independently required margin.
Flash Exposure Calculator
A direct-flash guide-number estimate relates aperture, subject distance and the chosen ISO reference.