Light Distance

Lower power closer to the plant. Why using extra energy when the result is the same! 😋

The greater depth of canopy, the more you will benefit from more power from further awy -- all other things the same -- meainng a well-distributed blanket of light etc. Due to how quickly light spreads out on 2 axes when you assess any plane a specific distance from light source, you will get better penetration deeper into a canopy with more power and further away. this is incontrovertibly true. How large of effect is something that needs to be measured in each context to make an educated guess at what is best for any situation. There's virtually no benefit when talking about short plants like very early vege and seedlings. The time to consider it would be during flower with a deep canopy. Using a scrog would delay that suggestion while things grow out horizontally. phone apps may not be accurate, but they are precise. You can see proportional intensity by taking a measurement at different depths of canopy. Obviously shielding from leaves and such plays a major role too in what you'll see. If it is 50% of a measurement above, it's 50% of umol/s too, even if the umol/s reading is wrong due to conversion errors taking place between lux and umol/s of PAR wavelengths. So, light intensity will 'fade' slower the deeper you go, if you use more power from higher distances that results in same PPFD at canopy of plants. Whether it is worth the extra cost is a totally different question that is much more complicated. The cause and effect here is real.. whether or not it matters is the real question. real life measurements would help... I doubt anything more than a few more inches would be helpful before the cost per added gram is too high to rationalize more watts. they key takeawy here is don't be blindly focused on trying to get your lights as close as possible through dimming.. that would be unwise in any context except tiny plants and a scrog or similar situation where the wanted growth resides in a small depth of space.