Got a flashlight and a lux meter? That’s all you need to measure beam patterns, throw, flood, and lumens!

Got a way to log the lux meter readings every minute? That’s all you need to measure runtimes!

Use this LibreOffice spreadsheet to calculate the lumens, throws, floods, and runtimes. Just fill in the green columns and the rest will be done by the spreadsheet.

If you want you can send me your data and I will publish them here.

AA Flashlights