is the lamp size important?

[eguaym]

I understand that more watts in a lamp more deeper the light can go, but what happen is for example you have two lamps with the same power (96 watts) but one is 20 inches and the other is 15 inches.

Or if you have flourecent lamp A (96 watt, 20 inches long) and fluorescent lamp B (65 watt, 10 inches long)

[Sanjay]

If you assume that the lamps are of equal wattage, and have the same spectral distribution, the size of the lamp will affect how the photons get distributed over the area. If you recall that PPFD is measured per square meter. A longer lamp will spread the photons over a larger area (this will especially be true if the measurements are taken at a distance where the point source rule does not apply). So even if the number of photon/sec generated by the 2 lamps may be equal, the PPFD will not since a long one will spread the photons out over a larger area.

sanjay.

[eguaym]

Thanks...