Which produces more light per watt?

[squidworth]

Do you only pick you light by the "strength". Would you not also consider the color rendering of a particular lamp? Metal halide has a pretty good CRI, but would you also use another lamp in conjunction with the Mh to get good color?

 

[ironreef]

Originally posted by anthem:
<strong>Still missing the point. Your trying to get a reading for something you believe in - that being lumens (or your interpretation of 'useable light'). Go ahead and pull any chart you want on lumens. The whole debate is that lumens doens't matter.
Ed</strong><hr></blockquote> I belive your missing the point I'm trying to make. I'm not debating lumens ect. I questioned the link saying which lighting had more lumens per bulb. Which I questioned. I put out another link that used the same units of measure which they both didn't match in saying what/which was more effienct. They measured in lumens. If i were to buy a bulb i would use the PPFD = light out put of quality and quanity of photosynthetic photon flux desity. The effieceincy is defined as the ratio of the ppfd to the input power. Some ppl use CRI to determine but maybe harder to measure in higher k bulbs. Most ppl use par and type of par=range of color to determine what they want. I would go with par intesity. Lumnes I never used for my decisions. If you read my post or understood what I was getting at the link provides wasn't accurate imo.

 

[mojo.]

geez. I was going to ask a question on how to light my 75 gln. Now I'm really confused!!!

 

[drkegel]

Here's some REAL techno mumbo-jumbo for ya'll, but it does prove that lumens only measure a SPECIFIC wavelength of the entire spectrum!
One lumen is the equivalent of 1.46 milliwatt (1.46 x 10-3 W) of radiant electromagnetic (EM) power at a frequency of 540 terahertz (540 THz or 5.40 x 1014 Hz). Reduced to SI base units, one lumen is equal to 0.00146 kilogram meter squared per second cubed (1.46 x 10-3 kg multiplied by m2 / s3).
THis is the link you can use to find the above info:
<a href="http://whatis.techtarget.com/definition/0,,sid9_gci541730,00.html" target="_blank">http://whatis.techtarget.com/definition/0,,sid9_gci541730,00.html</a>