Lockedin
Well-Known Member
Throwing in my $.02, having measured PAR and spread at multiple heights using COBs, mid power diode strips and boards, it is very evident that PAR remains relatively evenly spread with strips when adjusting height above canopy however PAR readings remain even from a ratio perspective , overall point measurements are lower as you get further away.
Boards, depending on shape and size act similay to strips but with more concentrated light in the center as the spread of the diodes over the prescribed coverage area is slightly less even than with strips due to the physical placement of the diodes with respect to the intended coverage area.
COBs, as @PSUAGRO. pointed out act almost like a projector beam with high photon flux output from a small area of densely packed diodes. These perform better at higher operating heights which allow the light to be more evenly spread over the intended coverage area. This is why COBs are generally used in high bay warehouse lighting as a replacement for HID/HPS/CMH style lights.
Penetration is a subjective measurement however absent of defoliation practices COBs arguably penetrate to lower branches better than mid power diodes. Similar to a garden hose with multiple settings, the ‘jet’ setting provides more strength to the water output than the ‘shower’ setting which spreads the water out more with less overall velocity and strength per sq mm.
I'm guessing that now would be a great time for a noob (me) to ask:
Wouldn't grow method also dictate light choice?
A. SCROG / SOG - I would think that spread would be paramount; the canopy is kept thin by design. --- A set of qb's or bars maybe.
B. Topped / Natural - the more directional light would potentially penetrate the canopy better. --- COBs / HID /
C. Defol - would enhance the penetration of any light. (sorry to bring the "D"efol word to this thread!
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