Shop lights

Discussion in 'The Shop' started by Gordon, Apr 5, 2018.

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  1. Jul 3, 2019 #81

    jack620

    jack620

    jack620

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    I just replaced twelve 36W 120cm/4ft flouro tubes in my workshop with 16W Osram LED tubes in daylight colour (6500K). I don't feel they are any brighter, but I prefer the colour to the old warm white tubes.
     
  2. Jul 16, 2019 #82

    Wizard69

    Wizard69

    Wizard69

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    Hi Cogsy;

    Little late responding.
    This is why I specifically mentioned that they dived into the blue is bad nonsense.
    Here in lies the problem wave length doesn't really matter, if the intensity is high enough you can get damage. If not damage, temporary blindness or disorientation. I've actually have had exposure to very high intensity 'RED' LED's and can attest to how bright those little guys can be. However what many need to understand here is that these are not consumer grade light sources.
    Even old fashion light sources like halogen projector bulbs can damage the eyes. This especially in the case of shielded bulbs that don't have UV filtering.
    The problem here is that you can make any wavelength of light a hazard by suitably concentrating it.
    Interestingly this point source issue has been brought up in other articles which unfortunately I could not find when I posted this one. In any event there is certianly a distance issue here as the eye has to be at a distance from the point source to create a point or illumination on the retina.
    It is true that there is nothing special about an LED but there is nothing special about a filament in an old fashion light bulb. There is a difference though in that the light isn't as multi directional as you think. In either case looking at and trying to focus on such light generators is not a good thing to do. I have to believe that your know this and hopefully everybody in this forum does also.
    I've actually have read a lot about this and stand by what I've said. Any damage that is going to happen is going to happen because you have an extremely intense light source and that such sources be they an LED, and old fashion bulb, Welders arc or whatever is not good for you to look at directly.
    Err no! It is poorly written that is for sure and likely is gleaning information from research they don't understand, but the main point is that correct. That is very high intensity light sources can be very bad for you.

    The problem is people really don't understand what very high intensity light sources are!!!! Beyond that trying to explain the the inverse square law is sometime futile. However in this hobby I think it is important to get people to respect high intensity light sources if they ever have an opportunity to work on one. Care should be taken for example in installing and adjusting a bulb in a profile projector or the like.

    Further what is important here is to realize there is a huge difference between a high intensity light source and a video monitor or even LED lighting. LED lighting solves the problem or a high intensity source by the use of diffusers.

    By the way LED's themselves are very interesting to read about. There are many approaches to getting the light out of the LED. This shapes the light projected from the LED which is why you can't really compare them to multi directional light sources like fluorescent or filament bulbs. LED's may not be lasers but they are also not homogeneous in the way that they perform.
     
  3. Jul 18, 2019 #83

    Cogsy

    Cogsy

    Cogsy

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    Hi Wizard,
    I'm not going to address your post point-by-point, and certainly not going to go through the thermodynamics as to why a 3W, 5W or even higher wattage LED can't thermally damage your eye, or go through the difference between (even 'high' intensity) LED light and narrow-band, phased LASER light emission, but instead I'm just going to elaborate on where I'm coming from on this topic. I have a degree in Physics and I'm currently doing post-grad research into ocular biophysics, which is likely to evolve into my PhD thesis topic. Without trying to be arrogant, I do assume that I have a little better background and understanding of this area than a layman, although I'm certainly not a world authority. If/where I am wrong I'm more than happy to be corrected, but the unreviewed site/article you originally linked to is very poor quality and is talking a large amount of bunk.

    LEDs' can be very bright, and as a general rule, if the brightness of any light source feels unpleasant, then don't look at it. As far as damaging your eyes from an LED in the manners described in that article - completely unsupported/ utter garbage.
     
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  4. Jul 18, 2019 #84

    bobden72

    bobden72

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    I am with you all the way Al well said. Down with scare mungers.
     
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