Ceramic Metal Halide (CMH)

[hoosierdaddy]

Surely testing equipment was involved in arriving at the spectrum analysis, be it IR or whatever. If I am following you correctly, you are claiming that the actual numbers of the test are not at all as what are shown. They have shifted the actual numbers and just placed the value of 100 at the tallest peak of each graph, yes?
This is in essence what you are claiming?
Are you simply making the assumption this has been done? You seem to see it as an obvious thing, with your scientific mind and all.

 

[cashmunny]

Surely testing equipment was involved in arriving at the spectrum analysis, be it IR or whatever. If I am following you correctly, you are claiming that the actual numbers of the test are not at all as what are shown. They have shifted the actual numbers and just placed the value of 100 at the tallest peak of each graph, yes?
This is in essence what you are claiming?
Are you simply making the assumption this has been done? You seem to see it as an obvious thing, with your scientific mind and all.

Yes, that's exactly what I'm saying. And the reason it is obvious I stated in my first (more technical) explanation. But I'll restate.

First off, and most imprtantly, they explicitely state that the units are relative. They are not using absolute units, like dollars earned per week in my analogy. They are using a relative fraction.

Second, even if they were plotting using the same scale and units, it would be extremely unlikely that the peak output in the visible spectrum would be the same number: in this case 100.

Thirdly, the area under these curves is a direct measure of all the light energy being emitted by the bulb in the visible spectrum. By looking at those curves, the area under the CMH curve is about ten times that of the HPS curve. I find that extremely unlikely to be the case for equal wattage bulbs given the simple fact that CMH bulbs do not outperform by a factor of 10, and also that, qualitatively speaking, they are about the same brightness. I could see a factor of two difference maybe, not a factor of ten. And that judgement is based on my experience of looking at charts and data of this sort every day, 40 hours a week, my entire career.

And as for my "scientific" mind I should have a scientific mind, I am a scientist, lol, If i didn't have a scientific mind I wouldn't have been able to do what I've done for the last twenty years.

 

[cashmunny]

This may be an even simpler analogy.

Let's say you and your friend are taking a Physics class. And your teacher is easy and his is hard. Both professors grade "on the curve".

You both take midterm exams. But they are different midterms, one written by the easy professor and one written by the hard professor.

The class average is 70% in the easy class. You get a 70 so you get a "C".

The class average in the hard class is 40%. Your friend gets a 40. He also get's a "C"

You both got the same grade. Someone comes along and doesn't know that one class was easy and another one hard. They only know the letter grade. How do they tell who is the better student? So if they only looked at that they wouldn't know.

But who really is the better student, the guy who got a "C" in the easy class or the guy who got a "C" in the hard class.

The point is that when you are employing a relative measure and that measure is relative to a specific group you can't go comparing relative measures from different groups that have their own, different, relative measure.

 

[cashmunny]

I'll also point out this in support of HPS. Since the energy of a photon is linearly dependent on frequency and since red light has a lower frequency than blue light, assuming a photosynthetic reaction is catalyzed by one photon, that process is less energy intensive for a process catalyzed by one red photon than a process catalyzed by one blue photon. So your energy goes further for red light than for bluelight assuming both photosynthetic processes use the same number of photons.

Now whether photosynthetic processes are equal in terms of the number of photons required is another discussion.

 

[whatissixbynine]

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[knna]

I think I posted this info earlier in this thread, but as its so long, Ill post it again.

Phillips SON T Plus 400W (HPS): 138 PAR Watts emitted, corresponding to 657 uE (micromols of photons per second) (56500lm bulb)

Phillips CMD 400W (Retrowhite) (CMH): 121.5 PAR W emitted, 555uE (34800lm bulb; I think it has improved lately)

(margin error +-7%).

This helps putting relative spectral graphs in perspective, by providing context of absolute emission of both bulbs.

Of course, this only relates to the light being emitted. 15% less photons emitted by the CMH (12% less energy). But it not says nothing about how plants use those photons. I think they use CMH spectrum better, so yielding difference dont correspond to that figure, and aditionally makes a difference about quality.

Those figures refers to the 400-700nm range, without taking into account other wavebands (violet, UV and far red), that still have some photosynthetic action and that are more present on the CMH spectrum than in HPS one. But I choosed to give the data that correspond to the graphs being commented.

BTW, for me one of the largest differences between both lamps is the percentage of heat released by Infrared rays (IR), way higher for HPS lamps, that makes more difficult to manage temps of the grow.

Anyway, what matter is final result. With a 400W equipment, the only thing any person need to know how each bulb work for himself is testing both. No any graph implied and very cheap to test.

 

[onegreenday]

Phillips could have made a mistake in the graph.
Corporations do make mistakes.

 

[cashmunny]

Phillips could have made a mistake in the graph.
Corporations do make mistakes.

Possibly, but in this business I'm skeptical. I think they are overstating their case by using relative units. So it could be just an omission. But as with anything, when someone is trying to sell you something, buyer beware.

But on the other hand results do speak for themselves. And the CMH lamp is clearly better for veg. Maybe even better for flower. I don't know about the latter, I haven't tried it. It seems the jury is still out.

 

[hoosierdaddy]

I am curious how you judge the light clearly better for veg?

As far as the jury being out...that gets said alot in here. Chart the anecdotes in this thread, omit the "jury outs" and those that have never actually used the bulb, and I think we see things are not so unclear.

 

[whatissixbynine]

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[tommyboi_420]

quick quesition...how soon can i stick my seedlings under my cmh bulb??,and how far up should it be???....right now i got 17 seedlings under 3 small reg bulbs..and there streching the shit out of em

 

[onegreenday]

Possibly, but in this business I'm skeptical. I think they are overstating their case by using relative units. So it could be just an omission. But as with anything, when someone is trying to sell you something, buyer beware.

But on the other hand results do speak for themselves. And the CMH lamp is clearly better for veg. Maybe even better for flower. I don't know about the latter, I haven't tried it. It seems the jury is still out.

I just trimmed up a Mandala Sadhu at 56 days
1st 28 days under 400 CMH; last 28 days under HPS.
I have not flowered this before
but the buds are real loose and leafy.
Hard to call them buds really.

The Durga mata under CMH was like this too
real loose and leafy.

I'm not liking it for flowering; sorry to say.

 

[Pinball Wizard]

quick quesition...how soon can i stick my seedlings under my cmh bulb??,and how far up should it be???....right now i got 17 seedings under 3 small reg bulbs..and there streching the shit out of em

I go 3 weeks vegging under weak ass T-12 fluorescent tube lights (6500k, no stretching) then switch to a 400 CMH and transplant...

you have to experiment with the height of the light...not all reflectors are created equal

... ... ...

 

[tommyboi_420]

I go 3 weeks vegging under weak ass T-12 fluorescent tube lights (6500k, no stretching) then switch to a 400 CMH and transplant...

you have to experiment with the height of the light...not all reflectors are created equal

... ... ...

"T-12 fluorescent tube lights ".....you talkin about some 2FT or 4FT lites..pinball????...then how far up for the CMH????.....and ty for ya first reply

 

[Pinball Wizard]

"T-12 fluorescent tube lights ".....you talkin about some 2FT or 4FT lites..pinball????...then how far up for the CMH????.....and ty for ya first reply

4ft, 40watt, dual bulb, 6500k, T-12 fluorescent tubes (common shop lights)..2 inches above the leaves for three weeks... ..T12's won't burn!

I start the 400 watt CMH out... 20+ inches up...and experiment from there....18/6 or 20/4 for about one week...and usually go 12/12 after 4 weeks of vegging.

 

[Bobby Stainless]

I just trimmed up a Mandala Sadhu at 56 days
1st 28 days under 400 CMH; last 28 days under HPS.
I have not flowered this before
but the buds are real loose and leafy.
Hard to call them buds really.

The Durga mata under CMH was like this too
real loose and leafy.

I'm not liking it for flowering; sorry to say.

Most of your structural flowering/bud building as done under HPS. You also cut your plants a week and a half too soon. Sadhu should go 65-70 days.

I have flowered multiple strains under CMH, and they flower just fine. The plants do better when HPS is introduced along with the CMH.

For example, I run a 1000 watt with a 400 right next to it, in my smaller room. I think the CMH is the contributing factor, for max trich production.

 

[hoosierdaddy]

I have started an ad hock test of sorts. I have the same plants flowered under CMH all the way through, and some until the last week of flower, when they are finished under the same wattage HPS. I also will have samples of HPS last two weeks and HPS last three weeks of flower.
Maybe not a full on test, as my flowering is a mixed 400wCMH/150wHPS spectrum to begin with.

I have used the CMH exclusively and yes, there are more leaves, but there is also more swollen up, hard as rocks calyx' that I do not seem to get with straight up HPS.
The leafy wispy buds I hear talked about...it has to be a genetic or grower issue. I have seen no evidence of thin wispy buds at all, with multiple strains.
Yes, I have had some leafy wispy plants...but it was definitely genetic.
I just grew out a F13 that was the worst specimen of a plant. Nearly no bud structure at all. Airy and light. Pitiful.
Had I just grew it alone, and did it with a CMH, I may well feel that the light sucked. Thing is, this plants sisters grew right along with her...and they are stellar keepers with fat ass hard buds and a very nice high.
The problem was genes, not lumens.

Back to the warnings about the deceptive marketing practices here....
(sorry, it irks the fuck out of me to see mud thrown in a mans thread...and IMO if someone is going to call out deception, then they better well be able to prove it, or move the fuck on. That is just my irked ass speaking here.
And yes, that kind of shit gets my boxers in a big bind...

cashmunny, I would like you to point out the deceptive practices in the following examples of SPD charts, please.
The first chart shows only RELATIVE ENERGY on the one axis, the same as the charts that have been in question...however, this chart overlaid the three samples on the same graph. Is this a deceptive practice, and how does it differ from the charts in question?

Also, I have other examples of SPD chart comparisons. Maybe you could explain whether these should be used as valid comparisons, or looked at as deceptive marketing?

First graph is a CMH, second is an HPS

Now the HPS compared to an enhanced HPS:

I noted in my reading that many of the spectral measuring devices have software that only lists the Y axes as UNITS. Would this not be fine to do if we are comparing the energy displayed by two bulbs in a comparative fashion?

 

[onegreenday]

well I plan another 1K Hortilux and
I can run the 400 cmh between the 2.
see how that works

 

[habeeb]

I used the red floro tubes from advanced, had great results last run, this time around, it somehow "burnt" the shit out of my flos leaves?

maybe there sensitive to something in the spectrum as I had the bulb half inch form the leaves ( cool to the touch ) ... not a nute def as you can see where the red bulb was from looking at a straight line of "burnt" leaves. just so crazy as I would not think a light could do this to any plant.. I also saw this as I switched one of the daylight floros for the red, and saw it the next day.

 

[onegreenday]

my durga mata under 400 CMH was 60 grams dry (decent meds too)
but I got 80 grams
under HPS and the buds were more solid
with less leafy trimmings; hence more bud weight.

I'll run some more and compare more..........