Sony a9 III Flash Timing Offset Calculator for Godox
Start with your own readings. Calculate the change, verify a frame, and save what works.
α9 III flash timing
Calculate a starting camera offset, then refine it with measured tests.
Sony a9 III flash timing offset calculator for Godox
First choose the shutter, aperture and ISO that give you the ambient background you want. Keep those settings and your preset Godox flash power fixed while calculating a starting camera offset and light distance from explicit timing assumptions. This refined version of the original calculator returns camera settings, offset, power, distance and a modeled Sekonic meter target. Enter one real full-pulse flash reference to compare complete shooting recipes; verify the result with camera tests.
- Enter your ambient camera exposure, model and preset manual flash power. Use an approximate original family duration table or enter t0.1 from your Sekonic. Add an isolated-flash meter reference at a known power, distance and ISO to solve distance and meter targets. Comparing other powers is optional.
- Review the delay and pulse-shape assumptions, then test the displayed offset and neighboring 20 µs settings.
- Verify the camera frame, adjust exposure or ND if needed, and save a measured profile for the exact setup.
Original AD200 1/16 duration = 154 µs; assumed delay = 500 µs; 1/4000 s exposure = 250 µs. The old formula gives 202 µs, which would put first light after the exposure under those assumptions. The refined triangular model chooses 440 µs as a starting test. This is a mathematical example, not a measured AD200 preset.
Does shutter speed calculate the camera offset?
Shutter duration is one input. The calculation also needs assumptions about the effective firing delay and flash pulse. Aperture, ISO and distance guide exposure but do not establish that timing profile.
Are the Godox AD duration presets verified?
No. The original AD100, AD200 and AD600 family tables are labeled approximations. AD400 requires a custom duration. A measured t0.1 improves one input but does not establish delay or pulse shape.
What about Godox V100S starting values?
The Godox V100 manual gives approximate Sony a9 III references of 160 µs with wireless off and 560 µs with wireless on. These remain labeled starting references; calculated pulse mode requires your own duration input.
Can moving the light guarantee that timing stays within range?
No. The distance planner estimates an exposure change using inverse-square falloff. Changing power can change the flash pulse, so retest timing after power or setup changes.
Learn the decision behind the setting.
By Dwayne of DNA Premium Portraits, Sacramento-area portrait photographer. See formulas, assumptions and equipment sources.
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