[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: watts vs. lumens

Date: Sun, 14 Mar 1999 07:39:00 -0500
From: krandall at world_std.com
Subject: watts vs. lumens

>But that's the problem.  Lumens are NOT a better measure than watts. Lumens
>measure only the visible part of the spectrum, which is the part of the
>spectrum least used by plants.  A lamp with good output in the areas of the
>spectrum used best by plants can have a low lumen rating, and still grow
>plants well. (Like purple-ish Gro-lux, etc.)  A lamp taht expendes most of
>its energy in the visible range will have less of the wave lengths that
>palnts use more efficintly, even though they look "brighter" to us.  


Although I agree with you in priciple (that is, the plant photosynthesis
response curve and the eye sensitivity response curve are different), I
think you should be a little more precise in the terminology, because red
and blue, which I believe you were refering to as the wavelengths that
plants use more efficiently, are also in the "visible" part of the
spectrum.  Or did you mean to say that ultraviolet and infrared were the
preferred wavelengths for plants?