Reflectors Reconsidered

Has anyone else come to question the effectiveness of most of the popular reflectors on the market?

I ask, because I've noticed that when a bulb is placed horizontal the result is a rectangular area of illumination. See, the ends of an HID don't give off light like an incandescent bulb. Instead, light radiates outward from the arc tube. So when we place this bulb in a reflector, it naturally gives of light in two directions. So while a 1000W HPS might cover 9' in one direction, it really covers about 5' in the other direction and the light is nowhere near as intense.

I have also noticed that major lighting manufacturers like Lithonia all use a vertical bulb inside a parabolic reflector. These reflectors take light from 360 deg around the arc tube and direct it downward in a circle. And I'm sure huge companies that manufacture lighting for 500,000 square foot factories are quite knowledgeable about how to provide even efficient lighting.

I'm beginning to wonder if placing a bulb horizontal isn't in fact more about space and appearance than about even lighting.

good question and i agree that its far more efficient used vert.

Well, you know, I have yet to see a flashlight that uses a horizontal bulb and a half pipe shaped reflector. And my Maglight sure can put down some intense light.

if you put the bulb in vertically and use a reflector to bounce the light you are using down,you will have to reflect ALL the light and no reflector is 100%. by mounting the light horizontally, only 1/2 needs to be reflected down and is subject to loss.since we have the lights so close to the subject,it works better. if they ever designed a flashlight to only throw a light 2-3 feet, a bulb mounted sideways would work better. same for a warehouse w/ 6 foot ceilings.
that being said, I have used a 150w HPS in a small area mounted vertical w/ the plants around it because I didnt have the height to mount it overhead.

mrmadcow said:

if you put the bulb in vertically and use a reflector to bounce the light you are using down,you will have to reflect ALL the light and no reflector is 100%. by mounting the light horizontally, only 1/2 needs to be reflected down and is subject to loss.since we have the lights so close to the subject,it works better. if they ever designed a flashlight to only throw a light 2-3 feet, a bulb mounted sideways would work better. same for a warehouse w/ 6 foot ceilings.
that being said, I have used a 150w HPS in a small area mounted vertical w/ the plants around it because I didnt have the height to mount it overhead.

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What you are saying is certainly true - there is a small loss in light efficiency. But, the horizontal bulb puts out light in an odd, oblong pattern.

While light is great parallel to the arc tube, it is crap on the two ends. So, while a 600W can light 5' in one direction it really can only light 3' in the other direction with any appreciable intensity. So, if you are trying to light a 10' X 6' area you will need 4 600W lights to have even coverage. While this is more light than you need, it is necessary for even coverage.

my homeboy at my local hydro shop said the Adjust-A-Wing Reflector is the bomb.

I put this ? to the test because I wondered the same thing and what I found was the light that was vertical with no reflector at all blew away the horizontal with a adjusta wing reflector hope that helps imagine if I had a vertical reflector

johndoecangrow said:

I put this ? to the test because I wondered the same thing and what I found was the light that was vertical with no reflector at all blew away the horizontal with a adjusta wing reflector hope that helps imagine if I had a vertical reflector

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Would you elaborate on this? How is your setup arranged? I am considering using a bare bulb and kind of making the whole ceiling into a giant reflector.

really what you need is a light meter to truly see a reflectors effectiveness there have been several people at other sites who have done this a couple years ago before the magnum hoods came out an back then it was the supersun2 for the best all around...az

RickWhite said:

Would you elaborate on this? How is your setup arranged? I am considering using a bare bulb and kind of making the whole ceiling into a giant reflector.

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Now im just confused , so are we saying its better to hang bulbs vertically or horizontally in a shade ????????
i run a 250w mh and 2x600w hps all in side mounted diamond reflectors.....................

Azgrow said:

really what you need is a light meter to truly see a reflectors effectiveness there have been several people at other sites who have done this a couple years ago before the magnum hoods came out an back then it was the supersun2 for the best all around...az

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I googled these reflectors and it looks like the Magnum is just a high quality standard reflector using a vertical bulb just as I have been suggesting.

Companies usually produce what they think will sell best. If most growers are sold by the idea of a space saving super intense fixture, that is what they will produce. But, if these fixtures are so great, why don't warehouses and factories with over 100 HIDs use them? And BTW, none of these buildings use over 400W lights except for outside in the parking lots and even then they are rare. And warehouse lights are laid out by engineers to provide even lighting everywhere.

The down side of something like a low bay reflector is their large size. But I think if one were to rig a number of these with remote ballasts one could get a much more even light spread than when using vertical reflectors.

Check out www.grainger.com for a large selection. You want to look at "low bay" reflectors. High bay reflectors are designed to be like 40' in the air and will give a beam that is too narrow. Also, many of these come with a special lens that scatters light.

ditch the reflector, just hang the bulb vertically i hear its the bomb thats what im doing using 2 digital 600watters looking to get close to three lbs off that with some TLC