lighting conversion data

conversion from foot-candles to w(watts) per m2(meter squared)
(for wavelengths of 400-850 nm(nanometers):

types of light multiply fc(foot candles) by:
-fluorescent
cool white 0.032
warm white 0.031
grow-lux plant light 0.069
grow-lux wide spectrum 0.047
agro-lite 0.043
vita-lite 0.041

hid(high intensity discharge)
mercury vapor 0.030
metal halide 0.037
high pressure sodium 0.036
low pressure sodium 0.023

incandescent
standard 0.093
mercury 0.065

daylight: 0.060

luminous flux: the rate of emission of light from a source with respect to the sensitivity of the human eye, measured in lumens.

illuminance: the luminous flux density incident on a surface, in lumens per square meter expressed in lux(lx). or lumens per square foot.(lm/ft2)

irradiane: the radiant flux density incident on a surface; that is, the radiant energy received by a surface. the units are watts per square meter(w/m2) or milliwatss per sqaure meter(mw/m2) or in watts or milliwatts per square foot.

luminous efficacy: the ratio of total luminous flux emitted by a lamp to the energy consumed expressed in lumens per watt (lm/w).

the best unit for expressing the energy requirement of a specific plant species is the irradiance expressed in milliwatts per sqaure meter or milliwatts per square foot(mw/m2,mw/ft2). it is the measure of the quantity of energy in wavelength band 400-700 nanometers(nm) received by the plants.

to more accurately compare different light sources, a meter that measures par(photosynthethically active radiation) is desirable. while the photometer measures the brightness sensation of the human gene, the par meter measures the energy in the 400-700 nanometers(nm) wavelengths received by plants.

note: re-post just to keep similar subject matter condensed.
the relative photosynthethic response ranges, apparently (no body of work can definitely say for all plants), ranges from ~350-850nm.

blue light:350-500nm
chlorophyll a catalyst
auxin catalyst
cell activity
split of water atom
influence on movement of plant

green/yellow500-650nm
limited to no response. plants reflect green light and so seem green to human eye. why green lights can be used @ dark w/out interrupting dark for plants. party lights are effective cheap option.

red light600-700
sugar production catalyst
chlorophyl b production catalyst/engine
seed germ signal
chloroplast adjustments to light
siganl light/dark times
chromosome catalyst/engine
soil composting enzyme catalyst

far red 700-780nm
signal seed dormancy
signals internode stretch

uvb already documented as catalyst for fruit end quality. ~ 300-400nm for uv.

thank you very much

Saved and cataloged.

This is good stuff. Everyone with a garden should know these conversions. Keep spreading the knowledge. Knowledge is power!

Nice information here (specially the second post for my personal understanding as I hadn't see the plant response to light ranges broken out like that before), but the conversions are very general since the irradiance by channel (by nm) really needs to be mapped out against the PAR action spectrum of the plant you are trying to grow.

The spectral distribution of any particular bulb can vary wildly, ie compare a typical HPS to a CMH HPS:






The CMH has a far better spectral distribution for photosynthis than a HPS, but a simplified conversion factor wouldn't show that, right?

to accurately measure the light source in relationship to how much light energy is actually absorbed by the plant, a pyranometer may be helpful:

measuring sunlight at earth's surface:build your own pyranometer:
http://www.pages.drexel.edu/~brooksdr/DRB_web_page/construction/pyranometer/pyranometer.htm

from:

This is a gold mine of cannabis growing laboratory research
https://www.icmag.com/ic/showpost.php?p=2469004&postcount=7

enjoy your garden!

hortilux blue

hortilux blue

The hortilux blue is similar to the CMH. Has any one used in flower? Veg is awsome!