How many lumens does the sun emit?

brettmccft0

brettmccft0

Well-Known Member
legallyflying said:
Only a newb focuses on lumens..unless your trying to decide what lights to install when remodeling your fucking kitchen.

Light is nothing more than electromagnetic radiation. The "light" we see radiating from the sun, or your grow bulbs is but a narrow sliver of the total amount of radiation being emitted. Humans needed a unit to measure the light we can see and thus the lumen was born.

Last time I checked, and correct me if I am wrong, I didn't see any eyeballs on my plants. Thus buying light bulbs based soley on lumens is as meaningless as debating which dog whistle would sound best to humans. It's about PAR, as that is the frequency of electromagnetic radiation plants "see", or more specifically, they can utilize to produce glucose from co2 and water.

Halogen bulbs produce a shit load of lumens but you don't see anyone growing plants with them.

The future is led's that can produce the appropriate frequencies of PAR for optimal growth. And you can bet that the newbs will come our in droves asking " how many lumens does that LED put out"
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Only a noob DOESN'T focus on lumens. Exactly what Bwpz said, you dont see ppl using LED because the light spectrum is perfect, but the strength of the light is shit, which is why you will grow bean stalks if you use one of those. Lumens in relation to temperature is just as, or even more important than the light spectrum being produced because you have much more control over that than the actual electromagnetic spectrum. You dont see people using halogen bulbs because they are so darn hot, cant remember the percentage but like 50% or more of the energy is lost as straight heat, so it has to be really far from your plant... not cuz the spectrum is really bad.
 
Red1966

Red1966

Well-Known Member
jackinthebox said:
Does anyone know the answer to this?
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I read somewhere it's about 100,000 lumens at noon on a clear day, but can be higher depending on location (dry desert, high altitude, etc.) My lights (600w MH) put out 56,000 lux 1 ft. from glass in reflector. The box the bulb came in said it puts out 72,000 lumen. I think 1 lux = 1 lumen. Of course both lumen and lux measure light visible to the human eye, not PAR. I just checked with my luxmeter. Outside I got a max of 18,000 at 4:25 PM on a overcast day. Gulf coast._________________ Looked it up.... 1 lx = 1 lm/m2 or 1 lx = 0.09290304 lm/ft2. I notice some are using lm/m2 and some are using lm/ft2. This is bound to cause confusion.
 
legallyflying

legallyflying

Well-Known Member
Yeah the lux to lumen conversion is tough as one is dimensionless while the other I believe is measures by one square foot.

I shoot for around 70k lux when flowering. I found when I get around 90 I don't get as many crystals or smell.
 
luni209

luni209

Member
[video=youtube;mnOSu5449xE]http://www.youtube.com/watch?v=mnOSu5449xE&feature=youtube_gdata_player[/video].can anybody give me any tips or pointers or upgrades? I want to turn part of my garage into a grow room but i dont know what to put on tha walls to make sure no light will be able to come in. Anybody? Please? Haha
 
brando980

brando980

Member
jfour said:
NO, but I spent the last 6 hours researching this. And theres no sites with the info nearly so high a search index as this one, I tagged it here, so in a few weeks after google picks up the addition someone searching for this specific info will find it. :)

Cheers
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Like myself!
 
A

althor

Well-Known Member
I know this thread is about as old as the sun but since it has been revived, no one seems to be accounting for the penetration of light the sun achieves. That is where lightbulbs fall well short.
 
legallyflying

legallyflying

Well-Known Member
true enough but i recall reading that the lux readings near the equator are about 70-80k.

its kind of a who gives a fuck question anyways. The only point is that you CAN have your bulbs to close to your plants.
 
longophil

longophil

Member
approx 100,000 per square meter on a bright sunny day - but obviously many variables - that is more or less perfect conditions
 
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