Ceramic Metal Halide (CMH)

[cashmunny]

if they were the same "nature" of lamp, then this would be true.

the lamps however are not directly transferable with one another, from a data perspective.

just because the wattages are nominally the same, the lumens output are substantially different, indicative of both variable light outputs and other forms of energy release, not documented in the graph (ie, heat).

that said, the graphs between any two non-comparable bulbs will definately integrate to a different value. We wouldnt expect a 400w metal halide to integrate equivalently to a 400w HPS...because there are other variables.

You could be right. But I have both a CMH 400W and a HPS 400W. I don't think the heat output could account for the MASSIVE difference in scale of those curves. Perhaps UV output might have something to do with it since higher frequencies are more energy dense.

But I would say the area under the curve of the HPS lamp is a tenth of the CMH lamp, which intuitively makes no sense to me.

Lumens shouldn't enter the picture though since those bear only an indirect relationship to the integral of power spectral density.

I guess what I'm saying is that if they used absolute units instead of relative units for the y axis of both curves so that you would be comparing apples to apples, the yellowish peak in the HPS curve would be way taller.

Or put another way, if the CMH curve was plotted relative to the HPS curve (rather than itself) the peaks would be much shorter.

It's pretty clear that what they've done is scale the power spectral density graphs so that the tallest peaks are roughly equal height. And in order to do that they have to employ different scale factors. Which is deceptive advertising. But that's par for the course in this business.

Personally I think the CMH bulb is a better bulb, but these graphs overstate the case.

 

[- ezra -]

I am not going to argue the point here, you guys can choose to interpret these graphs any way you want. I come from a science background, and its very obvious to me these graps are unscientific, but they do fool a lot of people, which is what they are designed to do.

All the best...

 

[messn'n'gommin']

A marketing surveyor approached a woman in a grocery store and asked her if she was buying the tube of toothpaste in her cart because of the advertising. The woman exclaimed that she was much to intelligent and discerning to buy any product because of any ad's she had seen. So, the man asked her what made her decide to buy it and the woman said, "Because I get 23% fewer cavities and it has MFP flouride."

Deceptive? Maybe, and maybe not, but, certainly not any more (or less) than any other manufacturer. I'm more interested in the results than I am with marketing tools. So far, I have yet to see any HID lamp of equal wattage compare to the CMH. The rest is just details. I would suggest that anyone try whatever lamp they want and let us know how it goes. That will sway me more than any companies "claims" on their product.

Namaste, mess

 

[cashmunny]

I am not going to argue the point here, you guys can choose to interpret these graphs any way you want. I come from a science background, and its very obvious to me these graps are unscientific, but they do fool a lot of people, which is what they are designed to do.

All the best...

I agree 100%, I also have a hard science degree. Those graphs are cleary bullshit because of the different vertical scaling employed.

Deceptive? Maybe, and maybe not, but, certainly not any more (or less) than any other manufacturer. I'm more interested in the results than I am with marketing tools. So far, I have yet to see any HID lamp of equal wattage compare to the CMH. The rest is just details. I would suggest that anyone try whatever lamp they want and let us know how it goes. That will sway me more than any companies "claims" on their product.

Namaste, mess

I personally think the CMH is great for vegging. Tight internodes for sure, and controls the stretch in first two weeks of 12/12. But I switched to HPS for the next six weeks. I'm going to stick the CMH back in for the final 2 weeks of flower and see if it makes a big difference.

 

[messn'n'gommin']

I personally think the CMH is great for vegging. Tight internodes for sure, and controls the stretch in first two weeks of 12/12. But I switched to HPS for the next six weeks. I'm going to stick the CMH back in for the final 2 weeks of flower and see if it makes a big difference.

Agreed, 100%! It all boils down to what works best for an individual's circumstances and preferences.

Namaste, mess

 

[Maj.Cottonmouth]

Ok this is totally confusing me, So we are talking about the two graphs in the first post of this thread correct?

They both start at 0 and go to 100 on the vertical in equal segments of 20. How is this misleading? Please forgive me as I do not have a science background but I would like to at least know what people are in opposition over.

Thanks

 

[cashmunny]

Ok this is totally confusing me, So we are talking about the two graphs in the first post of this thread correct?

They both start at 0 and go to 100 on the vertical in equal segments of 20. How is this misleading? Please forgive me as I do not have a science background but I would like to at least know what people are in opposition over.

Thanks

They are trying to present a graph that shows how much energy is contained in the light of the bulb at various colors (frequencies). But they have clearly distorted the curves by making one look smaller and one look bigger.

 

[hoosierdaddy]

I think it is showing what light is released by the bulb, not contained.

I too am like Maj...I see both axes being identically scaled. And I see a comparative of light color energy released. How is this graph skewed? Please don't tell me how it is obvious to the scientific mind. Explain the ruse to me verbatim.

 

[Maj.Cottonmouth]

I think it is showing what light is released by the bulb, not contained.

I too am like Maj...I see both axes being identically scaled. And I see a comparative of light color energy released. How is this graph skewed? Please don't tell me how it is obvious to the scientific mind. Explain the ruse to me verbatim.

Talk like I am 5 years old please

 

[cashmunny]

I think it is showing what light is released by the bulb, not contained.

I too am like Maj...I see both axes being identically scaled. And I see a comparative of light color energy released. How is this graph skewed? Please don't tell me how it is obvious to the scientific mind. Explain the ruse to me verbatim.

When I said the energy contained by the light I meant the energy in the photons themselves, not the bulbs. Each photon contains energy equal to the frequency times plancks constant.

The vertical axes of both graphs are plotted in "relative units" which means nothing unless you state relative to what. The correct units for the vertical axes would be Watts per Hertz. When plotted in these units the curve is known as a power spectral density function.

By using relative units they are just saying they have chosen a scale factor for the graph (which should be plotted in the correct units of watts per hertz) such that the tallest peak of each graph works out to be 100. This is called normalization. And the scale factors for each graph are DIFFERENT numbers. So it is not an apples to apples comparison.

Incidentally, normalization is the same process whereby in statistics, the pure gaussian function is scaled by a factor of 1/sqrt(2*pi) in order that the total probability sums to exactly 1.00

The reason I know that they are different scale factors is twofold. First of all it would be an amazing coincidence if when the same scale factor was applied to both the CMH and the HPS power spectral density functions, the tallest peak in the visible range for both curves turned out to be 100. So clearly the same scale factor has not been used on both curves. The yellowish peak in the HPS curve would be much higher if the same scale factor were used on both curves.

Secondly the area under each curve will be equal to the total power transmitted in the visible range of light. Looking at those curves it is obvious that the area under one curve is 10 times the area under the other curve. Now in order for it to be a fair comparison the lights would have to be the same wattage. So taken over all frequencies of the electromagnetic spectrum, the area under both curves should be equal. Now it may be true that a HPS lamp gives out more infrared and the CMH gives off more UV which is not shown in these curves because they are only charting visible light. But I'm pretty sure that in the visible range the CMH bulb does not radiate 10 times as much light energy as the HPS bulb. I have both bulbs in the same wattage, 400W , and that is definitely not the case.

Also someone mentioned lumens, or luminous intensity. Lumens are irrelevant for this discussion as has been correctly pointed out many times in this thread. Luminous intensity is a weighted measure of radiant flux where the weight function has to do with the response of the human eye. Plants don't "see" lumens, they see photosynthetically active photons. The luminous intensity weight function for what plants "see" would be completely different. But regardless, unweighted radiant flux is what these graphs are showing, not luminous flux.

That is why this is deceptive advertising. Which does not take away from the fact that the CMH bulb is clearly the better bulb, watt for watt, for vegging IMO. I think if these bulbs were available in 1000W, no one would ever use HPS for vegging again. Unless you like tall spindly plants, lol.

 

[whatissixbynine]

.

 

[hoosierdaddy]

Wow, cashmunny...Maj asked that we be explained to like we were 5 years old. He didn't ask that you explain it so we felt like we were 5.

Here's the thing...Like Maj, I see a graph using the exact same numbers in the exact same slots. The explanation of your theory depends on the multiple assumptions you are making.
Take your assumptions out of the equation and then try to explain how the graph is skewed.

I am still not buying what you are selling.

 

[amoril]

cashmunny, while I agree that the graphs are inaccurately normalized, I disagree that they are as misleading as you feel they are.

IMO, the point of the graphs is to represent the relative balance of the spectral output of the CMH versus a standard HPS bulb. To do this, theyve normalized both of their outputs, relative to their own peaks. This allows you to compare the relative light output of each bulb, by wavelength.

You wont know how powerful the bulbs are at 480nm, but youll know which bulb, comparatively, is emitting a higher percentage of its energy at that wavelength. This was the intent of the graph, in my opinion

 

[whatissixbynine]

.

 

[Bobby Stainless]

The CMH induces greater THC production. I have seen this over and over with my own eyes.

The HPS is good for flowering. Which is why I use 4 1000w HPSs, and a 3 400w CMHs, for 5200 watts of complete mixed spectrum.

1000HPS 400CMH 1000HPS 400CMH 1000HPS 400CMH 1000HPS

 

[- ezra -]

very indepth answer. thanks for clearing that up, i couldnt have explained it as well that...

When I said the energy contained by the light I meant the energy in the photons themselves, not the bulbs. Each photon contains energy equal to the frequency times plancks constant.

The vertical axes of both graphs are plotted in "relative units" which means nothing unless you state relative to what. The correct units for the vertical axes would be Watts per Hertz. When plotted in these units the curve is known as a power spectral density function.

By using relative units they are just saying they have chosen a scale factor for the graph (which should be plotted in the correct units of watts per hertz) such that the tallest peak of each graph works out to be 100. This is called normalization. And the scale factors for each graph are DIFFERENT numbers. So it is not an apples to apples comparison.

Incidentally, normalization is the same process whereby in statistics, the pure gaussian function is scaled by a factor of 1/sqrt(2*pi) in order that the total probability sums to exactly 1.00

The reason I know that they are different scale factors is twofold. First of all it would be an amazing coincidence if when the same scale factor was applied to both the CMH and the HPS power spectral density functions, the tallest peak in the visible range for both curves turned out to be 100. So clearly the same scale factor has not been used on both curves. The yellowish peak in the HPS curve would be much higher if the same scale factor were used on both curves.

Secondly the area under each curve will be equal to the total power transmitted in the visible range of light. Looking at those curves it is obvious that the area under one curve is 10 times the area under the other curve. Now in order for it to be a fair comparison the lights would have to be the same wattage. So taken over all frequencies of the electromagnetic spectrum, the area under both curves should be equal. Now it may be true that a HPS lamp gives out more infrared and the CMH gives off more UV which is not shown in these curves because they are only charting visible light. But I'm pretty sure that in the visible range the CMH bulb does not radiate 10 times as much light energy as the HPS bulb. I have both bulbs in the same wattage, 400W , and that is definitely not the case.

Also someone mentioned lumens, or luminous intensity. Lumens are irrelevant for this discussion as has been correctly pointed out many times in this thread. Luminous intensity is a weighted measure of radiant flux where the weight function has to do with the response of the human eye. Plants don't "see" lumens, they see photosynthetically active photons. The luminous intensity weight function for what plants "see" would be completely different. But regardless, unweighted radiant flux is what these graphs are showing, not luminous flux.

That is why this is deceptive advertising. Which does not take away from the fact that the CMH bulb is clearly the better bulb, watt for watt, for vegging IMO. I think if these bulbs were available in 1000W, no one would ever use HPS for vegging again. Unless you like tall spindly plants, lol.

 

[hoosierdaddy]

The vertical axes of both graphs are plotted in "relative units" which means nothing unless you state relative to what.

We may not know the units, but whatevery they may be aren't both light spectrum's shown with the same range of numbers?
Let's assume that the graph did state the units as "watts per hertz"...explain to me how naming the units would change where the spectrum points on the graph would be different? Naming the units changes the numbers of one or the other?

By using relative units they are just saying they have chosen a scale factor for the graph (which should be plotted in the correct units of watts per hertz) such that the tallest peak of each graph works out to be 100. This is called normalization. And the scale factors for each graph are DIFFERENT numbers. So it is not an apples to apples comparison.

I see no different numbers. I see the same numbers in the same positions on both graphs. You exclaimed different, now please explain different.

The reason I know that they are different scale factors is twofold. First of all it would be an amazing coincidence if when the same scale factor was applied to both the CMH and the HPS power spectral density functions, the tallest peak in the visible range for both curves turned out to be 100. So clearly the same scale factor has not been used on both curves. The yellowish peak in the HPS curve would be much higher if the same scale factor were used on both curves.

Again, explain the different scale factor. I see the same numbers in the same positions.

Secondly the area under each curve will be equal to the total power transmitted in the visible range of light. Looking at those curves it is obvious that the area under one curve is 10 times the area under the other curve.

Not at all obvious to me, and I bet I'm not alone.

Now in order for it to be a fair comparison the lights would have to be the same wattage.

Are you now claiming these would have been differnt wattage lights? And if so, do explain that.

But I'm pretty sure that in the visible range the CMH bulb does not radiate 10 times as much light energy as the HPS bulb. I have both bulbs in the same wattage, 400W , and that is definitely not the case.

Ah, so this does boil down to your "feelings" on the issue, rather than any hard data. Hard for me to buy a "definate" from an obscure anecdote....albeit the usual way of anecdotes.

That is why this is deceptive advertising. Which does not take away from the fact that the CMH bulb is clearly the better bulb, watt for watt, for vegging IMO. I think if these bulbs were available in 1000W, no one would ever use HPS for vegging again. Unless you like tall spindly plants, lol.

See, this is the part that really blows my mind. Y'all start harping on deceptive advertising, yet the real world results of these bulbs seems to correspond to the data we are being fed by the mfg. Things do seem to match their information, but when we take a good look at the info you are feeding and warning us about, it doesn't jive.
Does that not spark any sort of thought in your scientific mind? How would this play into a statistics model?

You know, I have had several discussions with folks who are certain that global warming will have us all under water in about ten years.
They also have these scientific laden arguments, smothered in anecdote and emotion. They also talk a good one....

 

[cashmunny]

You aren't understanding the points I'm making. But regardless, it's a great light no doubt. No disagreement there.

They're just hyping it up with charts that are complete bullshit that are directed at the scientifically unsophisticated. Like the entire industry...hell like all industries do...when they want to sell you their product.

It's just that in this case they don't need to...because it's a great product. So it doesn't matter.

 

[cashmunny]

cashmunny, while I agree that the graphs are inaccurately normalized, I disagree that they are as misleading as you feel they are.

IMO, the point of the graphs is to represent the relative balance of the spectral output of the CMH versus a standard HPS bulb. To do this, theyve normalized both of their outputs, relative to their own peaks. This allows you to compare the relative light output of each bulb, by wavelength.

You wont know how powerful the bulbs are at 480nm, but youll know which bulb, comparatively, is emitting a higher percentage of its energy at that wavelength. This was the intent of the graph, in my opinion

Well I guess I agree, in that the graphs are useful in terms of comparing the relative output of the bulb to other frequencies emitted by that same bulb.

However because of the different scaling used for the y axes of the two curves, it is tricky to compare the bulbs to each other using those curves. One would always have to keep in mind that each curve represents energy emitted relative to itself, not relative to the other bulb.

Or stated slightly differently, showing the two curves next to each other invites comparison, when the curves are not meant to be directly comparative to each other, only comparative with respect to frequencies emitted by the individual bulb itself.

So to the untrained eye, IMO it is deceptive. Because the untrained eye would automatically compare the two curves without realizing the different scale factors employed.

But I suppose reasonable people can disagree. CMH is still the best bulb hands down regardless of what any charts show or don't show.

 

[cashmunny]

Here's an analogy that is simple. Suppose you had two graphs. One plotted your income each week for all of 2007 and the other one plotted your weekly income for 2008. So depending on how much overtime you work there are going to be bumps and dips. Now let's say for 2007 your highest weekly income was $1000. You worked a bunch of overtime and did well. And you take the chart data of your weekly income and you divide every weeks income by $1000 so that your peak weekly income is exactly 1.00 and every other week is plotted as a fraction of that.

Now let's say you had even more yearly income in 2008. You got a raise and in some weeks you worked even more overtime and made $2000 during your peak week. You had to take some unpaid furlough in some other weeks so your income those weeks was zero. But despite the furloughs, the raise and the overtime made it so you made even more money in 2008 than in 2007. So for the chart of your weekly income you take every week and divide it by $2000, so that your peak income is 1.00 and every other week is expressed as a fraction of that. And the weeks in which you were furloughed, your income fraction is 0.00

So if a stranger were looking at the two plots next to each other:

1) That person would be unable to tell in which year you made more money, because each week is expressed as a relative fraction.

2) In 2008, the graph of your weekly income expressed as a relative fraction of your peak, would be more spiky. There would be dips corresponding to the weeks you were furloughed and made nothing. And there would be peaks in which you worked overtime and made a lot. But those peaks would be the same height as the peaks in 2007, because again we are talking about relative fraction.

So even if the 2007 weekly income graph expressed as a fraction of peak income is smoother and the peaks are just as tall as the 2008 relative income graph, YOU ACTUALLY MADE LESS MONEY IN 2007.

The ONLY thing you can tell from looking at the graphs side by side, is which year had more variation in weekly income. But for the purposes of someone who doesn't know your total income, you could be a millionaire and they wouldn't know it. You could have won the lottery in the 20th week of 2008 and your income that week was one million dollars. But that week would still be expressed as a relative fraction of 1.00

It is impossible to discern yearly salary or even tell whether or not you made more money in any given week in 2007 or 2008. Because the scale factors are different for each graph. In the case of 2007 the scale factor is 1/$1000 and in 2008 the scale factor is 1/$2000

And that's about as simple as I can make it.