PPFD is the instantaneous photon flux reaching one square meter each second; DLI is the total photons accumulated over the photoperiod. Commercial growers need both because a crop responds to light intensity over time, not to fixture wattage alone.
A PAR map shows whether the canopy is receiving an even intensity and reveals hot/cold spots. Measure at crop height, because hanging distance changes PPFD dramatically.
DLI combines PPFD with hours of light. A lower PPFD over a longer photoperiod can deliver a similar DLI, subject to crop physiology and operating constraints.
For “PPFD vs. DLI: Which Metric Matters for Indoor Farm Lighting?,” these three models give you concrete products to compare against the requirements above, instead of leaving the answer at theory.
Our strongest starting point because its high-output full-spectrum led / dimmable format makes it relevant when translating the lighting metric above into a real fixture choice.
A useful second comparison because its bar-style led / dimmable high-output fixture format makes it relevant when translating the lighting metric above into a real fixture choice.
A contrasting third option because its multi-bar led / dimmable format makes it relevant when translating the lighting metric above into a real fixture choice.