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    Lighting White Paper

    I don't know if this is the proper place for this or not, however, I know a lot of folks here are electricians (which I am not) and have a different perspective on this type of material.

    I wrote a white paper on outdoor LED lighting and wanted anyone with an interest in lighting to throw some input my way. I still need to do some editing for grammar and such, but otherwise feel it is fairly complete. I had also tried to post the text and photos to this site, but my white paper was too long and the forum wouldn't accept it (Thus the external link).

    The link below goes to my Google Docs account. I am not trying to drive up hits to any website or promote any business or service. I have eliminated my name from the paper as well as the name of the company that I work for. I have left the fixture manufacturer's name as I felt that was pertinent to the paper itself.

    Again, I appreciate any input you may have to make my paper better.

    Link: Link
    I know lots about lightbulbs!

    #2
    Not a bad summation. I would add a close up of each fixture taken from your car seat to illustrate glare to the driver, an important factor when installing this type of lighting. The Cooper Lighting people recently hosted our company at an LED dog and pony show focused on their outdoor product lines. The performance of their LED pole fixtures was very impressive. The evenness of the light patterns and the Max to Min ratios blew metal halide away. Add the instant on nature of LED lighting and the ability to provide step dimming in a parking lot and I became a convert.

    Comment


      #3
      I've said this over and over on a few forums but cameras are not very effective at evaluating lighting performance, even subjectively.

      Record a light source from full output to minimum output and at the same time, observe the change. Then, watch the video. They will not look anything alike.

      Take a picture at full output. Leave camera's exposure settings manually held (ISO, F stop and shutter speed) so that you get a photo that looks bright but not overexposed. Now, dim down to minimum. Take pics in the same settings.
      The picture will look much darker than the lamp appears.

      This establishes that even using fixed settings, camera does not accurately convey brightness as we see it and to get it match what you see, you'll have to mess with exposure settings so that photograph looks approximately the same as how you see it in person, but at that point, it becomes way too subjective.

      When I made a field visit to pilot project street that uses LED street lights in place of HIDs, it was noticeably harder to navigate.

      It isn't just MH/HPS vs LED either. The fixture is a big part of it. A HPS fixture with high performance optics with characteristics desirable for application will outperform very basic HPS fixture of the same wattage you can find.

      Comment


        #4
        All LED fixtures are not created equal. The method each manufacturer uses to control light and glare are as varied as the the manufactures themselves. Some are using a totally new fixture designed from the ground up to control LED light sources and other are buying existing HID housing and throwing a driver and some LEDs into it and calling it a new fixture with whatever distribution. (just as with the Induction lighting market)

        Pictures can illustrate the relative performance of different light sources especially with respect to hot spots and glare.

        Comment


          #5
          Originally posted by Electric-Light View Post
          When I made a field visit to pilot project street that uses LED street lights in place of HIDs, it was noticeably harder to navigate.
          That is no more an accurate evaluation then using a camera.


          Your feeling that it is 'it was noticeably harder to navigate' is entirely subjective and also suspect considering that was the result you wanted / expected.

          Comment


            #6
            Originally posted by BullsnPyrs View Post
            Not a bad summation. I would add a close up of each fixture taken from your car seat to illustrate glare to the driver, an important factor when installing this type of lighting.
            Not a bad idea. Though, at least in this instance, the glare isn't really important. It's not a 24/7 facility and closes at 8. So it would only really matter for a few hours in the winter.

            I've said this over and over on a few forums but cameras are not very effective at evaluating lighting performance, even subjectively....
            I thought the photos were pretty fair. Again, I think the huge mistake lighting manufacturers make is that they take photos of a lit fixture. If you look at my photos you can see how the photos with and without the fixtures differ. The ones without the fixtures in the foreground are pretty honest. And while I understand that no photo can take the place of being there and seeing it, I can't provide everyone a plane ticket and short tour of Syracuse.

            I also wanted to hire a professional photographer to take the pictures. I have friend who I know in the industry and she was going to charge me next to nothing. But the company wouldn't let me expense it so I got these shots which, admittedly, are sub-par.

            It isn't just MH/HPS vs LED either. The fixture is a big part of it. A HPS fixture with high performance optics with characteristics desirable for application will outperform very basic HPS fixture of the same wattage you can find.
            I don't doubt this at all. There's no doubt that the HPS fixtures wasted lots of light.

            The method each manufacturer uses to control light and glare are as varied as the the manufactures themselves.
            Once again with the glare. Yeah, behind a lens it;s not bad. But when we've used LED replacement lamps, say BR30 or MR16, the glare is intense. I wouldn't dare use this stuff indoors where it could shine on people. In a Jewlery case or gas station refrigerator, sure.
            I know lots about lightbulbs!

            Comment


              #7
              Originally posted by TNBaer View Post
              Once again with the glare. Yeah, behind a lens it;s not bad. But when we've used LED replacement lamps, say BR30 or MR16, the glare is intense. I wouldn't dare use this stuff indoors where it could shine on people. In a Jewlery case or gas station refrigerator, sure.
              I wouldn't suggest using a retrofit LED lamp, they are only useful in recessed cans, (IMO) I would suggest an LED fixture designed with the appropriate optics

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