Can any science gurus enlighten me on light penetration?

[Dr.StickyFingers]

Lets say just for example I have 9 CoB leds driven soft compared to 4 driven hard (we can use CFL and Hid as an example too im just using leds as an example).

Lets for arguments sake say that the wattage, light output and light spread were also the same

Would there be any difference in light penetration between the two? What is penetration dependent on? spread, intensity, type of light?
I keep hearing people tell me if I take a 400 watt HPS it will have more penetration than a 400 true watt LED light (or a cfl, not really thinking about cfls though...). Why is this?

This is just something that''s been on my mind

 

[churchhaze]

The better spread would produce better results assuming the light sources were equal in both output power and spectral distribution.

 

[Tim Fox]

Agreed

The better spread would produce better results assuming the light sources were equal in both output power and spectral distribution.

 

[Dr.StickyFingers]

The better spread would produce better results assuming the light sources were equal in both output power and spectral distribution.

Yea I completely agree but I'm asking about penetration?

 

[Captain Ron]

Oohhh like growing!!!
From the thread title
I thought you meant like just putting the head in

 

[Captain Ron]

Yea I completely agree but I'm asking about penetration?

theres that penetration on yer mind again

 

[Tim Fox]

Yea I completely agree but I'm asking about penetration?

Well here is the rub,,, if you were to ask this question in the bulb rooms the bulb guys will tell you hands down that HID/ HPS outperforms LED any day of the week and penetrates better.,, you go and ask that same question over in the LED forums indoor growing and the LED guys will tell you that watt per watt that LED's penetrate better. after all the forums I have read, and after all the pictures of complete grows I have seen, ( thousands and thousands) ,,,
I have no reservations telling you that watt per watt LED's outperform HPS for yeild weight and bud density and penetration, you can get a better coverage with the same watts of LED and better PAR output, , then there is the savings in electricity and the lower heat levels,, where again LED wins, go over to the LED section and search for CXA3070 cobs or take a look at this guys grow using LED's
https://www.rollitup.org/t/diy-led-grow-lights-with-cree-cxa3070-cobs-and-cpu-coolers.805681/
any ways, its going to come down to opinions but my opinion has been made up after spending time chatting with the LED guys, and now having ventured into the DIY world of top bin cobs

 

[M0ps]

Spread of light correlates to the intensity and ability to penetrate the canopy. More spread = Less ability to penetrate. I've seen people recommend reflectors for the COBs, and you can also keep those LEDs pretty close to the canopy to reduce the spread. This may also help http://en.wikipedia.org/wiki/Inverse-square_law