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Thread: Inductive Lighting

  1. #76
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    Re: Inductive Lighting

    Kelvin is the color rendering temp. for white light. White light is a blending of all visible light. The more blue wavelengths in the light the higher the kelvin number. The more red wavelengths in the light the lower the number. Over 95% of all PAR wavelengths are in the visible spectra and thus correctly measured via the kelvin scale if it is a "white light".

    I am curious as to where you got the idea that "plant chlorophyll absorption spectrums that are predominantly outside of the visible spectrums". A few post down I created a thread titled "Green Light Induces Shade Avoidance Symptoms". It contains links to a number of peer reviewed articles and university coursework. The following link will help most people greatly in the basic understanding of light and plant interaction: Light

  2. #77
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    Re: Inductive Lighting

    Your link proves to illustrate my previous statement that very little chlorophyll absorption occurs between 500-600nm the human visual spectrum that we recognize as perceived colors after photons strike the surface of the object we are looking at and return color to our eye. The accuracy of that color measured against the light source putting out the light is measured as color rendering index 'CRI' with 100 being the highest value in terms color accuracy to the eye. Sunlight is the best for determining the color accuracy of the object we are looking at.

    Plant lighting requires an entirely different criteria that unless the indoor gardener is aware of the distinctions will waste a fortune in manufacturers claims that their products mimic nature in blissful ignorance of plant photobiology. Allow me to elaborate:

    lumens is for humans. kelvin, cri, lux, fc mean very little, with the exception of the carotenoid region, to determining if the light we are providing the plants meets its optimum daily UV/B-R/FR/IR spectral absorption requirements. Mfg's providing only lux, lumen, fc values have not given you any PAR intensity values and if they provide only CRI/Kelvin values they have not given you any PAR spectrum values to do a side by side lamp comparison.

    For plant lighting you really want to know the number of photons striking a meter squared every second that measure between 400-700 nanometers. This 'moment in time' reading is the photosynthetic photon flux 'pff' reading for photon intensity within the 400-700nm plant action spectra.

    When measuring pff over the course of a day it becomes photosynthetic photon flux density 'pffd' or how many photons within the PAR region contributed to the plants optimum photosynthetic absorption over the daily photoperiod. The Daily Light Integral 'DLI' for 'flowering' Cannabis is in the 20-25 Moles per day range. Lamps should ideally achieve these levels without Mole oversaturation or wasting too much energy (ie heat) above PAR (ie 1000watt HPS) to achieve optimum DLI.

    Another thing to remember is that we see within the 500-600 nm spectrum so photons within the 400 -700 nm wavelength regions need to be weighted for plant spectra not visible. When using a quantum meter the readings will be in uMoles that uses an algorithm to lower the photon values in the 500-600 nm visible regions and apply uMoles (intensity as measured in the number of photons within PAR that are striking the sensor surface) to the plants UV/B and R/FR/IR regions where photosynthetic action spectra is most necessary. It is for these reasons that a better measurement, still not perfect, of lamp performance would be the manufacturers stating the pff/w rating of their lamps so the gardener would know what to expect within the PAR regions

    The physics of light can be difficult to understand. Adding to the complexity is that plant lighting requires an understanding of plant photobiology and a completely different way of measuring that light compared to general area lighting. For years manufacturers have relied on those complexities and a myriad of competing technologies to promote some special feature of their lamps. What is really a pisser is how often these latest and greatest technologies have relied on design obsolence (ie lamp change outs especially for the indoor gardener) and how these 'improvements' never result in lower lamp prices. hmmmmmm???
    Icemud likes this.

  3. #78
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    Re: Inductive Lighting

    I don't want to copy and paste the post that I just completed so I'll simply link it.

    Lumens Vs Color Temp?

    Long story short, you have very few facts in that statement and a lot of misunderstandings.

    I see you edited your above post so I will do the same. You obviously only looked at the pictures and got confused. The top picture is only showing you how a wavelength is measured. not a cutout of the picture below that is showing the visible wavelengths. For a more clear statement (straight from the link below the pictures).

    "If you remember that visible light covers the range of wavelengths from 400 to 700 nm, then you can see here that sunlight includes waves that are ultraviolet (280 to 400 nm) and waves that are infrared (greater than 700 nm)."
    Last edited by Hosebomber; 10-13-2012 at 12:02 PM. Reason: more concise

  4. #79
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    Re: Inductive Lighting

    Lumens are for Humans as we see colors best in the 520 - 610 regions where very little chlorophyll absorption takes place. The regions to the left and right of these spectrums allow some small levels of visual acuity they are as limited to the same degree plant's absorb a small percentage of those wavelengths in the regions in which we see. I favor broad spectrum lamps that allow a natural photomorphogenesis as the plant's photoperiod is changed. The whole thing about switching lamps based in Kelvin is a longstanding marketing gimmick to sell more lamps. Low kelvin value lamps still are weighted to UV more so than red.

    Correct me if I'm wrong here but it seems to me that your asserting growers would be okay selecting their grow lamps in Kelvin values and not referring to spectral distribution graphs.

  5. #80
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    Re: Inductive Lighting

    That is not what I'm saying at all. Getting all of the information about a product that you can makes you an informed educated consumer. Never take anything a company (or person for that matter) tells you at face value. The lighting industry ( incandescent, CFL, Tube, and HID) as a whole is rather mature and has set standards that they test at. LED producers do as well but that does not apply to panel/grow light producers.

    On a technical aspect, Humans see (normal humans without optical problems) from roughly 380nm to 740nm. Nearly all humans see 400-700nm. The suns peak wavelength is nominally measured at 502nm. Low Kelvin values are skewed more to red than UV. THe higher the number the more blue hue they contain. Color temperature - Wikipedia, the free encyclopedia Does a pretty good job of explaining this concept. It's not really a gimmick or marketing ploy to change the light. It is more, a set standard of measurement used by an industry and growers trying to mimic seasonal change based off of that set industry standard.

  6. #81
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    Re: Inductive Lighting

    Hi, i've been doing a lot of research since I'm new to growing and my local grow store tried to sell me on these new induction lights.. They seem to be pretty pricy but look pretty cool and last a very long time without having to replace the bulb.. What is the real deal with these? since I'm new I'm not sure what to think or compare to

    PLEASE HELP

  7. #82
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    Re: Inductive Lighting

    You can find the exact same product for about half the price from the Chinese company that produces them.

  8. #83
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    Re: Inductive Lighting

    Do you have a link to that company? I'd like to check it out.

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