Flash Sync Speed Calculator
Maximum full-open mechanical sync reciprocalHz1/(actual curtain travel time+independent margin), not flashpulseHSS or guarantee artifact free timing.
Description
A nominal full-open mechanical flash-sync frequency depends on curtain travel and an independently required margin.
A nominal full-open mechanical flash-sync frequency depends on curtain travel and an independently required margin.1
This tool calculates the reciprocal total duration without modeling high-speed-sync pulses or guaranteeing a clean exposure.
When to use Flash Sync Speed Calculator
Use this tool to calculate the reciprocal total duration without modeling high-speed-sync pulses or guaranteeing a clean exposure.
How to use Flash Sync Speed Calculator and how it works
- Prepare actualFullCurtainTravelSeconds, callerIndependentlyRequiredSyncMarginSeconds, with the units, conventions and assumptions below.
- Enter the required fields and run Flash Sync Speed 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 |
|---|---|---|---|
| actualFullCurtainTravelSeconds | Actual Full Curtain Travel Seconds. Use the units and matching context stated in the calculation below. | number | Required; strictly positive; finite; other constraints below |
| callerIndependentlyRequiredSyncMarginSeconds | Caller Independently Required Sync Margin Seconds. Use the units and matching context stated in the calculation below. | number | Required; nonnegative; finite; other constraints below |
Supply positive curtain travel time and nonnegative additional margin in seconds. Return the reciprocal of their sum in reciprocal seconds, representing the corresponding shutter-speed denominator. This does not establish a camera-specific flash-sync limit or model flash duration.
speedReciprocalSeconds=1/(curtainTravelSeconds+marginSeconds) 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 | Reciprocal shutter duration in inverse seconds. | number |
{
"input": {
"actualFullCurtainTravelSeconds": 0.01,
"callerIndependentlyRequiredSyncMarginSeconds": 0
},
"output": {
"result": {
"value": 100
}
}
}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 Exposure Calculator for a complementary operation: A direct-flash guide-number estimate relates aperture, subject distance and the chosen ISO reference.
Use Depth of Field Far Limit Calculator for a complementary operation: A thin-lens far depth-of-field limit depends on a separately established hyperfocal model and matched distance units.
References
-
Flash Sync Speed Calculator — tool.io
Similar or alternative tools
- Flash Exposure Calculator
A direct-flash guide-number estimate relates aperture, subject distance and the chosen ISO reference.
- Depth of Field Far Limit Calculator
A thin-lens far depth-of-field limit depends on a separately established hyperfocal model and matched distance units.