Why spend $$$ on a flowering lamp if you have a $ veg lamp?

Prawn Connery

Well-Known Member
You've been growing far, far longer than I, so I normally wouldn't attempt to correct you, but on one issue - and one issue only - I'll give it the old college try...

Penetration is more an effect of diffusion than intensity. Because of this, strips and boards can achieve greater penetration than point-source lighting (alternatively, one or more COBs per square foot can also achieve excellent penetration). The old paradigm is slowly changing, but it is well-entrenched in our minds, so it's not going without a fight. See the article below for support of my assertion.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4559655/
You are entirely correct: diffusion allows light to hit parts of the plant that might otherwise be shaded from direct light. I haven't seen that study before, so it makes interesting reading. Thanks.

I believe it also contributes to one of the theories behind why most plants are green: because green, being the most efficient spectra in terms of photosynthesis, is reflected and diffused by the plant itself to the undergrowth and deep canopy, where even small amounts of green light can be efficiently photosynthesised.

You have touched on one of the advantages of panel and strip lights. That is, multiple sources of light reduce shading and are able to penetrate through canopies by shining (diffusing) light at different angles, creating a more even spread of light that is more efficiently photosynthesised.

But it's worth noting, the inverse square law still applies: that is, more intense points of light carry that intensity deeper into the canopy so long as they are not blocked (shaded). Simply put, diffuse light spreads more rapidly, casting a wider area of illumination, but less powerful the greater the distance compared to a comparable single light source.

I don't want to confuse the issue, but inside a tent (or reflective room), diffused light will tend to spread out and hit the walls and reflect back into the canopy. There are reflective losses associated with this that direct light does not suffer from. One way to counter this is to move the (diffused) light closer to the canopy to reduce wall reflective losses. You can do this with strips and panels because the light and heat is spread more evenly. COBs, by design, cannot be mounted too close to the canopy. COBs can also suffer from refractive losses as they pass through a lens, but strip lights also have lenses and you have to assume that all light fixtures get dirty over time and a COB is easier to clean than rows of multiple 3030 LEDs.

Pros and cons to both.
 
Top