20w v maxes replacing 91w sox-e

[thorncollector]

Hello All, just this week 91w sox-e (17000 lumens) has been replaced by single chevron 20w v maxes which put out 2000 lumen. how can this possibly be satisfactory especially as they are on 10m columns.
regards john

[Ash]

1. They are LED therefore automatically better

2. They save nearly 80% energy

3. The White high CRI light is objectively better (quoting Max from Ligthing Gallery) than the no-CRI SOX light

4. If comparing LED lens panels vs. "classic" SOX designs, with the LEDs less of the light is lost away towards the sky etc, so somewhat more is directed to the road. (however, with the design restrictions imposed by the need to cool the LEDs, the possible optical designs for LEDs are all very glary unlike that of SOX)

[Dave]

Your last comment that less light is lost to the sky is completely not true. Its been shown and proven that LED's are actually causing loads more light pollution, the light sky effect is getting worse. I've seen multiple newspaper articles and even reports on the internet outlining this problem. The whole reason is the fact they're so directional, and the fact they're practically a daylight colour output. Where SOX only can reflect off two coloured surfaced, white and yellow, LED reflects off everything. SOX lighting causes minimal to no light pollution at all, just the fact they're semi cut-off immediately goes against them, but sadly to brainwash people they have to say SOX, SON causes it. Its complete and utter rubbish imo, but I guess they have to blame something, typically its the older, more proven stuff. All that determines light pollution is optic type and lamp colour.

The only reason they're saving 80% energy is because they aren't installing the right wattage replacements, its all a case of bringing the wattage down as far as they can to even try and justify that LED is better than old proven technology. Crunching the numbers, 35w SOX is 200 lumens output, where LED is only 83 lumens. In every aspect, LED does not match older technologies one bit, and it annoys me so much when people try to big it up to me.

[Kev]

Ash is being sarcastic Dave lol

[Ash]

Except point 4.

My point was not about sky light pollution from reflected light, but about light emitted directly from the luminaire into the sky. Classical SOX lanterns do emit bigger relative part (i.e. percent) of their light output directly into the sky vs. flat LED panels. Accordingly, the LED panels get bigger relative part of their light output down onto the road

This is the only thing, that really improves the efficiency of the LEDs a little..

But it would be as true (and even truer, due to better optics than LEDs) for a more modern design SOX lantern - that unfortunately dont seem to have caught on, i dont know why

By better design i dont say FCO. But have a look at something interesting :

- Take a SOX lantern like a Beta 5. The lamp is in the bowl. Quite a bit of the light is emitted so way high up, where it is allready useless. The refractors help, but when they are located on the sides of the bowl, they do it by sacrificing small part of the light (throwing it further up) to get the rest of it down

- Take a HID lantern like a Beta 79. The lamp is entirely in the upper housing. The lantern is not FCO - there is a drop bowl with refractors on the bottom, and they too lose a little light upwards. But it is much less compared to the Beta 5. Optically it is much more efficient

Something like a Beta 79-ish design with a SOX in it, or the same Beta 5 but with deeper upper housing that actually contains the lamp, and modified refractor pattern for the different lamp position, would be exacly the better lantern design

Formally an FCO would be even better, but it will have more limited light distribution and not as good glare control. The limited distribution means that more light is getting to overilluminate some spot on the Earth closer to the lantern, so more of it is reflected to the sky... Which pretty much cancels out the expected "full" FCO advantage for the dark sky

Overall, i think that something with a drop bowl and possibly only minimal refractors (where most justified, like Beta 79) would be the better design, than both extremes - "full" FCO or "full" refractor (like US cobrahead)

As for the LED panels, they provide quite some uniformity on the empty road - that looks nice in the pictures maybe. But they do it at the price of very high glare. Bad enough with just LEDs on a PCB, but the lenses actually focus it in your direction at an angle along the road (typ. you get the laser in the eye when entering into the angle of 70deg from the luminaire)

Now think of it :

1. When you look in the day at a scene where some things are under direct sunlight and some are in the shadow, you see greatly both of them. The Lux level difference there is easily as high as 100X for "light" shadow (under a tree) or 1000X for "dark place" (e.g. looking into the entrance of a building from a sun lit outside, or looking outside from within the building). Our vision handles the 100X without a blink, and the 1000X still very well. There is no point to bring uniformity in road lighting to ridiculously high standards like 2X.... All it serves is only when taking the promotional picture. Nothing more

2. Light levels on most roads could be dropped 10X (like from the 91W SOX to the 20W LED... But i'm not about SOX vs LED here, so let's compare equal light type sources for the matter) and you'd still be able to SEE. You just will JUDGE the road as being too poorly lit. And the light levels are chosen for the most part to satisfy the latter. But for that, it's once again not the uniformity that matters, but the average light level. It might be very uniform, or maybe some patches are under-lit but some others are lit brightly enough to not give it an overall gloomy appearance. Ok, so the uniformity doesn't serve to allow lower light levels (and so saving energy) either

3. When there is something on the road but you are blinded by a LED panel, you will drive straight into it without seeing it, no matter how "well" the road is lit.... Especially so, when the LED panel is after the obstacle, so it lights up brightly its other side but not the side that is facing you

None of the lighting experts in the LED trade will agree with any of the latter points

[AngryHorse]

All the 'Road safety', and optics and stuff has been forgotten about now, energy bills are not going to go down again, ever!, and on this current trend in the coming years they'll remove street lighting all together!!
Your councils don't actually have to provide you with street lighting at all from what I understand?