kerneldrop
Flashlight Enthusiast
You mean the earth isn't flat?
It's inconclusive…each side has convincing evidence
You mean the earth isn't flat?
No, @jtr1962 is going back and forth on his position. First he argues that higher CCT provides better visual acuity providing a study using fluorescents and another study on HPS and MH. And using those studies he tries to argue for high CCT LED. He then supports a position that studies like that aren't relevant by supporting your comment on SPD and the UMTRI study.A lot of what you are saying JTR is correct
That is exactly what happened, they also cut up perfectly good poles and installed crappy ones that are not as long,. Pure corruption and greasing hands. there is no other explanation.Problem is your management probably hired whatever electrician they normally use, he recommended some cheap lights he makes good margin on, used some stupid 2:1 "rule of thumb" to convert from HPS watts to LED watts, and well now you have a crap lighting system. When the original fixtures were put in for your parking lot, it is almost a given that an engineer or lighting designer did a proper analysis and picked specific fixtures, pole heights, and worked with pole spacing limitations to create a compliant lighting setup.
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I take that all back if you used to have side of wall wallpacks. They are a pain in the rear when replacing. Many jurisdictions have lighting ordinances and those old wall packs are no compliant. When you replace them, you are supposed to use full cut-off enclosures (no uplight). That again takes someone who knows what they are doing to select a proper fixture.
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Of course, I also see idiots put up wickedly bright LED fixtures, generally cheap off-shore imports, and mount them on swivel mounts and have them 30+ degrees of horizontal and the end up lighting up the neighborhood. I am currently in the process of giving someone an education about that. I suspect they are going to have to rip out $20,000 of lighting. I don't feel a bit bad though, they cut corners, and their residential neighbors are being punished for it.
To quote Alaric,
The well researched experts like @Alaric Darconville and @-Virgil- sound quite open towards lower blue light and possibly street lights as well.Feel free to search this cite for where us (actual lighting experts) pilloried the AMA, their joke of a statement, their lack of qualification of said statement, and the lack of consideration of requirements.
Continuously lighting highways is a poor/questionable practice, btw.RP8 standards for street lighting all define lighting levels that fall by a large majority into the mesoptic range for the intended target areas, i.e. the street, and sidewalks, however, keep in mind, these averages may be as low for low pedestrian conflict local roads as 0.3 cd/m^2 with a 6:1 min/max which means getting to 0.05 real world, from target sources. Scotopic is 0.01, so you don't have to be far off the target areas to get to 0.01 especially when the goal of modern lighting is limited light trespass. On the other hand, for highways, the minimum can be as high as 1 cd/m^2, with a 3:1, which means we are pushing over 3, hence into photopic.
And Caltrans' experience with ridding themselves of continous expressway lighting.Previously the Nord-pas-de-Calais in 2007 region switched off lighting on the A16 route to Belgium but the state and local authority have yet to decide how to split the savings.
According to road monitors the DIRIF, the number of accidents dropped by 30% as a result of the change.
"Cars go slower and the drivers are more aware," said a spokesman for the DIRIF.
In the 1970s, in response to an energy crisis, CalTrans decided to remove all roadway lighting from limited access freeways, except for those located at the interchange. In the 30 years since these roadway lights were taken down, CalTrans has not seen the need to reinstall roadway lighting on freeways. CalTrans has now commissioned a study, due for completion in 2008, to determine whether roadway lighting is necessary even at interchanges.
Guess what? UMTRI conducted another study with LED! Here are their findings.
Ultimately, the same properties are at play. The more blue a light source has, the more glare it will produce. Even though that chart showed a spectrum normalized for a black body, it still is relevant. The chart you linked also illustrates that even providing perfect CRI and SPD while increasing CCT will still increase glare.
But hey, @jtr1962, now that we're throwing out any study since it wasn't done with LEDs, I assume we're also going to be throwing out the two studies you linked in the beginning with high CCT fluorescents?
Continuously lighting highways is a poor/questionable practice, btw.
And Caltrans' experience with ridding themselves of continous expressway lighting.
That's all well and good, but it seems to me that it's better to move away from human vision and use infrared machine vision. In the event that the night vision device fails, the gearbox is blocked at a maximum speed of 20 km / h
Something like this
That's all well and good, but it seems to me that it's better to move away from human vision and use infrared machine vision. In the event that the night vision device fails, the gearbox is blocked at a maximum speed of 20 km / h
Something like this
What are you talking about? Both UMTRI studies showed more blue light producing more glare.And this is NOT the conclusions you jumped to from the last study that were not actually in that study.
Guess what you can also do? You can also cut down CCT while further cutting down blue. Any sort of improvements of cutting down the blue spike could be applied to lower CCT products to bring their blue light content even lower, e.g. the voilet pump Sunlike.We can tailor light sources to reduce deepish blue (the pump color), while still providing significant rod response, and by virtue of how CCT is calculated, it will still have a relatively high CCT, but will not produce as much discomfort glare response from blue cone stimulus, but will be perceived as bright due to IPRGC stimulus.
Making claims without any links to peer reviewed studies, like what your commentary has been, doesn't move the conversation forward.Throwing out random papers and isolated facts without understanding their full meaning and implications is doing little to move the conversation forward.
No, @jtr1962 is going back and forth on his position. First he argues that higher CCT provides better visual acuity providing a study using fluorescents and another study on HPS and MH. And using those studies he tries to argue for high CCT LED. He then supports a position that studies like that aren't relevant by supporting your comment on SPD and the UMTRI study.
You brought up expressway lighting, and I brought up experience and studies from various DOT's showing that as questionable lighting design. Don't be coy.And that adds to the conversation how?
This comment right here.I don't perceive he has at all. However, I do see you putting out papers and drawing conclusions that are either not supported by the data in the paper and/or are irrelevant to the discussion.
What are you talking about? Both UMTRI studies showed more blue light producing more glare.
Guess what you can also do? You can also cut down CCT while further cutting down blue. Any sort of improvements of cutting down the blue spike could be applied to lower CCT products to bring their blue light content even lower, e.g. the voilet pump Sunlike.
Making claims without any links to peer reviewed studies, like what your commentary has been, doesn't move the conversation forward.
I have consistently followed and carefully quoted the results of the linked studies. You haven't provided anything other then commentary.I do see you putting out papers and drawing conclusions that are either not supported by the data in the paper and/or are irrelevant to the discussion.
Yes, I'm sure I too will rise to the standard of random internet person making un-researched/un-verifiraible claims on the internet.Feel free to get an education, and a few years of experience, and then you will be able to find and research the papers that validate everything I say and actually understand what I am saying. Till then, I have wasted enough time on you.