You haven't shown anything. You have made hypothesis based on a few basic concepts. That's all fine and sound. But let's be clear, you illustrated it in paint. You have not shown, proven, or even tested anything. You conveniently leave out any imperfections by your walls...but point out any shortcomings of a designated reflector.
I have argued that in MOST situations a lot more light hits the reflectors instead of the walls. Whether reflectors actually work better than reflective walls depends on the efficiency of the used reflectors and/or reflective walls. That's it. Nothing wrong with any of that. Nothing hypothesis about it either.
Only bit of hypothesis I offered was that highly and direct reflective materials work better than a piece of semi-translucent flat white plastic. That's based on test results though. Not tested by me, but still.
That drawing is more like a Venn diagram than anything else. Simply an effort to explain a point better than just with words alone. It's pretty clear that more light hits the reflectors in most grow rooms (apart from very small ones).
BTW I didn't even start this, alesh did. Clearly he also instinctively felt something was wrong with the currently ongoing reflector hype. I was just left with the ensuing angry horde.
So which is better or worse, first trying to figure out the fundamental physics that apply or just test something without keeping the physics of it all in mind and then draw false conclusions from those tests? Especially without even questioning the rather staggering test results themselves?
It's not that easy to get those tests done properly. Taking a few PPFD measurements doesn't really say enough. The average PPFD jumping up by 20% to 30% only from using a reflector should also start alarm bells go off that something is wrong with the test. Or at least prompt the question where that light was lost in the situation without a reflector.
For instance calculate up front what you think the PPFD should be and then compare to the test results to see if you were right. If not, then why not.
When the question comes up to estimate average PPFD we work with 5 to 10% wall reflection losses when using COBs and average PPFD tests tend to confirm that (when using reflective walls). Then it "turns out" that reflectors actually "create" 20 to 30% more light. How could that possible be if you lose only 5 to 10% to begin with? Wall reflection losses would need to be around 25 to 40% for that to actually be correct. So obviously something does not add up there. I'l offer another hypothesis, it shows how poorly diamond pattern walls perform. Although that was also a finding from the above mentioned reflectance test.
You also cannot simply add matrices of a handful sqft sector spot measurements to claim good light distribution when the light isn't distributed evenly over those sqft sectors.
I have done plenty of light distribution and reflection tests to know how easy it is to get it wrong. I have seen led sellers come up with average PPFD values 10% higher than the "PPF divided by the surface area" as well. Somehow people just don't seem to get the strict relationship between PPF and PPFD. Keeping that in mind should help to at least catch those testing errors.
You should read professional large scale test reports. They keep so much in mind and measure everything meticulously. For example when testing different spectral distributions they measure chemical composition of the plants and their nutrient uptake. Turns out that a different spectrum can mean plants also need different nutrients. There are also differences in stomatal conductance and therefore CO2 uptake and transpiration. Obviously since the chemical composition can differ, the taste of the produce can be different also. A test with added FR light resulted in noticeably sweeter tomatoes (ie people would pick them out as being tastiest in a blind taste test).
Of course it's fun to test things. I love testing things and try something new with just about every grow. Though we need to be aware of the limitations of our small scale tests. I never pretend my tests prove anything conclusively. Most of the times I will say it's more an indication that something might work and perhaps only in certain situations. For instance by adding a phrase like "when using highly reflective walls". Sometimes I even have to admit that I cannot say what caused the results when others are already going wild over the results and contribute it to a single factor.
I understand it can be annoying when someone explains that things went wrong with your test, but shooting the messenger won't improve the tests.
