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Mono vs LED streetlights? Any point?


Space_Plane
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Hello hello, 

Have quite enjoyed tinkering away at imaging the last few years, especially as a distraction during lockdown etc, but recently the council have decided to install ludicrously bright led streetlights all along my street. Where once I had a fairly dark and usable back garden, now I have 3+ floodlights staring down at it (they also saw fit to change the lights physical position).

I image with osc, have been considering mono for a while, but it would require significant outlay. Is it + narrowband filters of ANY help whatsoever with led lights? Or is it just a lost cause? There are so many I don't think there's any point contacting them about it. 

Alternatively any good filters for osc that anyone has found particularly effective against leds?

Any thoughts welcome!

Cheers

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NB imaging helps with any sort of light pollution.

However, I don't think all is lost in your case. As far as I can tell - your main problem now is that flood lights shine down on your garden.

I think that you should concentrate on providing shielding for your imaging rig in the first place. Put it in artificial shadow. Couple of lights, especially if directed downward, won't create much of "airborne" light pollution - glow of air above your location. It will create problems if they are shining directly at your scope - and that is what you should try to solve first. Maybe creating some sort of portable shielding - something like this:

slaettoe-privacy-screen-outdoor-black-br

 

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LED street lights have actually improved my back garden. Despite them being nigh on impossible to filter.
When I moved to this house, there were low pressure sodium lights. Monochrome orange  that is easily filtered, but poor fittings with a lot of spread.
Then things went downhill as they got replaced by high pressure sodium, which emits a lot of different wavelengths. Again in poorly designed fittings that spread the light.
Now the LED lighting means you can read a book on the main street (why I don't know) but the fittings are well designed.
They put the light on the road and pavement. Not my back garden.
Unfortunately I am very much in the minority.

I think a letter to your local light pollution agency is called for. Otherwise known as the council.
Point out there is light pollution in your garden. It is obstrusive light trespass on to your property.
You don't have to say why you want your garden dark. If there is pollution or trespass, those key words should trigger a response.
Ask them to put light where it is intended. On the street and not your garden.
If they waffle or become evasive you can take it further.
There a quite a few threads on here with success stories.

You may gather from my response that Nottinghamshire County Council, my local polluters, are not on my Christmas card list.

Good luck and keep us posted.

David.

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After the council installed an LED street light at front of our house I contacted them about the light intrusion into our garden, within a month they had come out and dimmed the light so our garden is now back in darkness, well done West Wilts Council, now anyone found the off switch for all the clouds?

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Led street lights improved things, but then came the issues when low power and cost lighting allowed every man and his dog to mount high power flood lights everywhere. Not to mention those twodecorative ones that point directly upwards and should be made illegal. So all in all the led situation has made things better and then worse. 

Edited by Adam J
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Hi all, thanks for your replies / suggestions. 

There are a couple of places in the garden where I can setup that are not directly in the line of sight of the streetlights (albeit limiting my field of view), so unfortunately it is actually their glow I am finding worse.  It is quite a main road in front of my house, and as such they are taller and much brighter than the more "residential" led lights in the streets behind, which I cannot really see at all.  They also face outward at a slight angle, and not fully downward, which seems to make it worse.

Is the general consensus then that they are not effectively "filter-able", via mono/narrowband or otherwise?  Shall reconsider contacting the powers that be, but I suspect it'll be a waste of my time!

Thanks again

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13 minutes ago, Space_Plane said:

Shall reconsider contacting the powers that be, but I suspect it'll be a waste of my time!

I think that is sensible course of action.

14 minutes ago, Space_Plane said:

Is the general consensus then that they are not effectively "filter-able", via mono/narrowband or otherwise? 

Narrowband filters help a lot - regardless of the type of light pollution - as long as you image targets that give off light in that particular band - which is emission type nebulae.

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What I would say to you is that when it comes to broad band light pollution from LEDs I have found that the quality of the filers rejection (OD) is almost as important as its bandwidth.  Hence my AD 5nm filters are better than you would expect them to be in comparison to something like a 6.5nm optolong filter if you compared them on band pass alone. 

Adam

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If you look at the spectrum  of an LED streetlight,  there is an intense blue band (loads of scatter) but less emission towards the green, so a filter passing just this wavelength should improve signal to background ratio.

Chris

 

 

 

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IDAS D2 works wih LED street lights as well as tungsten, sodium and mercury vapour. I have one for my OSC and it works well. As far as I am aware this is the only one on the market at the moment.

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Thanks again for all your input, certainly some things to think about.  That IDAS D2 looks interesting, and worth a try, likely much more effective than the l-pro I use.  A lot of my recent images have otherwise been taken with an l-enhance, and I've only done one proper session with it and my new led friends.  I'll post a rough process of that up later if interested, but what started me thinking down this line was the large section of white glare toward the bottom of the image...right above where the led lights are 🙄

Judging by your comments, if I postponed mono, for now, do you think a replacement duo filter with narrower bandpass might be more effective?

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I had a problem with led lighting. Was real bad glare. Emailed a polite query to the council. (Bexley) explained I do astrophotography and the problem and asked could they put a shield on the lamp.  Within a week they put a side shade on. Unfortunately that only cut it down by 50%. I wrote giving an update and thanked them again and said about only 50% block. The came and fut another shade on the rear too and now I have none. Of course it's been cloudy since but where my scope can only go is glare free. It's always worth asking as nothing to lose. Clear skies. 

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39 minutes ago, Space_Plane said:

Thanks again for all your input, certainly some things to think about.  That IDAS D2 looks interesting, and worth a try, likely much more effective than the l-pro I use.  A lot of my recent images have otherwise been taken with an l-enhance, and I've only done one proper session with it and my new led friends.  I'll post a rough process of that up later if interested, but what started me thinking down this line was the large section of white glare toward the bottom of the image...right above where the led lights are 🙄

Judging by your comments, if I postponed mono, for now, do you think a replacement duo filter with narrower bandpass might be more effective?

The l-extreme has two 6nm bandpasses and does a great job with LP.

Mono, with individual emission line filters would likely do a better job, but would be much more expensive and take longer to gather data.

Edited by Jm1973
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If you are imaging emission nebulae with NB then it shouldn't take any longer than with broad band filters as the emission lines are likely to be narrower than your filter's bandwidth, so won't be cut off by the filter.

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