Flash Light Spill Mapper & Power Solver
Start with your own readings. Calculate the change, verify a frame, and save what works.
Light spill mapper
Find power changes from measured contributions at three points.
Map where each flash contributes before changing power
A face, outfit and backdrop may receive light from several sources. The spill mapper uses isolated meter readings at three regions to solve bounded power changes for separate brightness goals.
- Turn on one light at a time and meter all three regions consistently.
- Repeat for the other lights, then enter the regional changes you want.
- Inspect the predicted mismatch and supported settings, then remeasure after adjustment.
If every light contributes to the face and backdrop in the same proportion, power changes cannot independently brighten the face and darken the backdrop. Placement, feathering or flags must change first.
Why does the result show a best fit rather than an exact plan?
The measured contributions and power limits may make the targets inseparable or unreachable. The tool reports remaining error instead of treating a compromise as exact.
Can I use readings with ambient included?
This solver assumes negligible ambient and isolated flash contributions. Mixing ambient into each input would double-count it and invalidate the model.
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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