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hairmetal4ever

Different reflector types

hairmetal4ever
9 years ago

Trying to do some calculations.
I once had a 1000 W Metal Halide fixture (magnetic) and a square-shaped Sunlight Supply reflector. I am trying to determine the difference between that type of reflector, and the large "parabolic" reflectors that are about 48" wide, like this one below. Mainly as far as:
Shape of light coverage area?

Intensity of light at various differences, and, does the intensity drop off at the same rate?

Other things to note?

Comments (4)

  • hairmetal4ever
    Original Author
    9 years ago

    Here's the reflector I'm talking about, or those like it.

    Here is a link that might be useful: Parabolic reflector

  • MisterK
    9 years ago

    The sun system reflector focuses the light more, which means more lumens per square foot on a smaller footprint. The parabolic reflector spreads light into a larger area, with less lumens per square foot.

    Keep in mind that reflectors also focus heat right into the plant canopy. Light coverage also isnt even under the reflector, this caused by the very nature of point source lighting such as mh and mh. I grow without a reflector, bulb suspended vertically, dropped low enough to light up plant sides, for 360 degree coverage. This creates a doughnut shaped canopy around the bulb and all light is used. Thats the most efficient use of light. Important when youre paying for it.

    Some people argue that the light bouncing off the reflector adds to intensity but it adds more heat than anything else. Once you get the hang of vertical growing, whatever it is you were growing, youll be growing 2.5 times more of it using the same amount of power :)

  • SouthCountryGuy Zone 4b-5 SE BC
    9 years ago

    Hairmetal4ever - I am not really sure exactly which reflector you are using right now to comment if it will be better or worse than a parabolic. The key thing to note is that the smaller the reflector the more efficient it is because the light doesn't have to travel as far to be reflected.

    How are you dealing with heat? I never got into the fancy cooling systems and found when I was running 1000w MH my bulbs had to be quite a distance from my plants. So, for me, it was more important to have more focused light. Light intensity does fall off at the same rate which is why you want to concentrate it from the source.

    I totally disagree that it is more efficient to grow with out reflectors. Running the lamp in the horizontal position with a reflector can nearly double your light intensity. I agree that if you are paying for it you may as well use it so it is best to reflect the light from the direction you are not using it, as in straight up.

    If you do try the parabolic reflector you can always test your light intensity with a camera if you don't have a light meter. If you need help doing this let me know. It isn't as accurate as a light meter but will give you some pretty good ball park numbers.

    SCG

  • SouthCountryGuy Zone 4b-5 SE BC
    9 years ago

    Hairmetal4ever - I am not really sure exactly which reflector you are using right now to comment if it will be better or worse than a parabolic. The key thing to note is that the smaller the reflector the more efficient it is because the light doesn't have to travel as far to be reflected.

    How are you dealing with heat? I never got into the fancy cooling systems and found when I was running 1000w MH my bulbs had to be quite a distance from my plants. So, for me, it was more important to have more focused light. Light intensity does fall off at the same rate which is why you want to concentrate it from the source.

    I totally disagree that it is more efficient to grow with out reflectors. Running the lamp in the horizontal position with a reflector can nearly double your light intensity. I agree that if you are paying for it you may as well use it so it is best to reflect the light from the direction you are not using it, as in straight up.

    If you do try the parabolic reflector you can always test your light intensity with a camera if you don't have a light meter. If you need help doing this let me know. It isn't as accurate as a light meter but will give you some pretty good ball park numbers.

    SCG