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Light pollution filter for observing in NYC area?

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#1 Diomedes

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Posted 24 February 2020 - 12:20 PM

I know the best thing to do is to drive to an area that's less light polluted. However, I got access to my apartment's roof and I live on the last floor. So it's really convenient to just go up half a flight of stairs and be close to home. I noted that through naked eye observing I can only see stars up to magnitude 4(very very very faint). Binoculars are great at allowing me to see more, and I was able to locate M35 using my 70mm Meade. The M35 cluster was just bright enough for me to see it but I don't feel like I got to enjoy it as much.  I have a very cheap light pollution filter(https://www.amazon.c...e?ie=UTF8&psc=1) that does not seem to help much. 

 

when it comes to light pollution would more aperture lead to better views ? or would an increase in aperture be just as bad due to the light pollution being amplified along with the target. 

 

 

I saw a post in CN from 2015 discussing this topic but I'm wondering if they are any recent filters that do a better job. 


Edited by Diomedes, 24 February 2020 - 01:31 PM.


#2 Dave Mitsky

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Posted 24 February 2020 - 12:38 PM

Broadband light pollution reduction filters may help somewhat but mainly on nebulae.  However, the advent of widespread LED lighting is going to reduce the effectiveness of both LPR and nebula filters.

 

https://www.prairiea...ep-sky-objects/

 

https://www.prairiea...common-nebulae/


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#3 macdonjh

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Posted 24 February 2020 - 12:40 PM

I don't like broad band, or light pollution, filters.  Like you, I didn't think mine did much to help, and it turned everything blue.  If I wanted funky colored stars, I'd save my money for night vision (I know, SOTA night vision is white now, not green).

 

One thing more aperture will get you is enough light gathering to use narrow band filters, like the Lumicon UHC, Orion UltraBlock, NPB by whoever makes that and their variants.  

 

Another thing to consider is electronic assisted astronomy.


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#4 JoshUrban

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Posted 24 February 2020 - 12:42 PM

Hey there!

 

  Urban astronomy (conveniently fits with my last name - ha!) is very doable, and in fact, can be rewarding in different ways than dark sky viewing.  I often observe from downtown Washington, DC, doing outreach, and there's plenty of stuff to be seen! 

 

  Is your scope 70mm?  An increase in aperture will definitely help. I'm forever recommending the 6" dob!  BUT - sure, a bigger scope WILL show you more, but the best scope is the one that's currently in your living room, whatever that may be.  So get outside and catch some photons one way or another!

 

  Some filters darken the sky too much for little scopes (although there's conflicting reports on this, as some people will use them with the unaided eye to see big objects like the California nebula from a dark site.)  So, I'd look into that before you buy as well. 

 

  I'm sure someone on here has used the link you posted.  I'd suggest maybe spending a bit more, and getting something from Orion or Lumicon - good brand names for astro gear. This one looks pretty good https://optcorp.com/...oCM4cQAvD_BwE  

 

  I personally use an Orion UHC (ultra high contrast) and an Astronomik OIII filter with a bigger scope.  They work great on nebulae!  

 

  One way or another, keep on looking up!  There's much to be seen!


Edited by JoshUrban, 24 February 2020 - 12:46 PM.

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#5 macdonjh

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Posted 24 February 2020 - 12:43 PM

Broadband light pollution reduction filters may help somewhat but mainly on nebulae.  However, the advent of widespread LED lighting is going to reduce the effectiveness of both LPR and nebula filters.

 

https://www.prairiea...ep-sky-objects/

 

https://www.prairiea...common-nebulae/

Interesting point.  There is one area which could give us hope.  I recently visited the Bay Area and made the pilgrimage up Mt. Hamilton to visit Lick Observatory.  The speaker said the observatory is having success in the Santa Clara Valley getting the various municipalities to at least install full cut-off shields when they switch to LED lighting.

 

I grew up out there and remember well when Lick Observatory was successful getting the cities to switch to low pressure sodium lighting, since it has a narrow emission band and is relatively easy to filter out.


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#6 Dave Mitsky

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Posted 24 February 2020 - 01:05 PM

when it comes to light pollution would more aperture lead to better views ? or would an increase in aperture be just as bad due to the light pollution being amplified along with the target.

A larger aperture allows greater magnification at the same exit pupil and is one way to somewhat reduce the effects of light pollution.  

 

https://www.skyandte...elescope-myths/  (myth #2)


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#7 Diomedes

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Posted 24 February 2020 - 01:05 PM

Funny you mentioned electronic assisted astronomy, I was just looking at https://www.revoluti...cts/products/r2

 

I don't like broad band, or light pollution, filters.  Like you, I didn't think mine did much to help, and it turned everything blue.  If I wanted funky colored stars, I'd save my money for night vision (I know, SOTA night vision is white now, not green).

 

One thing more aperture will get you is enough light gathering to use narrow band filters, like the Lumicon UHC, Orion UltraBlock, NPB by whoever makes that and their variants.  

 

Another thing to consider is electronic assisted astronomy.



#8 39.1N84.5W

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Posted 24 February 2020 - 01:06 PM

Diomedes... you +could+ get into EAA observing. There's a specialty subforum for this here on CN. I wouldn't buy more aperture. Instead learn how to take pictures and then "live stack" them on software like Sharpcap.
It's a longer learning curve, yes. But you can be observing galaxies and nebula and other objects in your heavy light pollution with these techniques.
Clear skies

#9 Diomedes

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Posted 24 February 2020 - 01:07 PM

thanks for the links, my next telescope is going to be a 8" Cat. My current one is a 70mm meade.  

 

Hey there!

 

  Urban astronomy (conveniently fits with my last name - ha!) is very doable, and in fact, can be rewarding in different ways than dark sky viewing.  I often observe from downtown Washington, DC, doing outreach, and there's plenty of stuff to be seen! 

 

  Is your scope 70mm?  An increase in aperture will definitely help. I'm forever recommending the 6" dob!  BUT - sure, a bigger scope WILL show you more, but the best scope is the one that's currently in your living room, whatever that may be.  So get outside and catch some photons one way or another!

 

  Some filters darken the sky too much for little scopes (although there's conflicting reports on this, as some people will use them with the unaided eye to see big objects like the California nebula from a dark site.)  So, I'd look into that before you buy as well. 

 

  I'm sure someone on here has used the link you posted.  I'd suggest maybe spending a bit more, and getting something from Orion or Lumicon - good brand names for astro gear. This one looks pretty good https://optcorp.com/...oCM4cQAvD_BwE  

 

  I personally use an Orion UHC (ultra high contrast) and an Astronomik OIII filter with a bigger scope.  They work great on nebulae!  

 

  One way or another, keep on looking up!  There's much to be seen!



#10 Diomedes

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Posted 24 February 2020 - 01:08 PM

Hey, I have been using deep sky stacker and my DSLR. It really does allow you to see so much more of the sky.

 

Diomedes... you +could+ get into EAA observing. There's a specialty subforum for this here on CN. I wouldn't buy more aperture. Instead learn how to take pictures and then "live stack" them on software like Sharpcap.
It's a longer learning curve, yes. But you can be observing galaxies and nebula and other objects in your heavy light pollution with these techniques.
Clear skies



#11 sg6

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Posted 24 February 2020 - 01:10 PM

The filter you link to appears to basically cut out the sodium wavelengths, 589nm.

Since these days I expect little to be the old sodium yellow it will have limited effect. Much these days are mercury, and LED and assorted others.

 

As it reads you are somewhat above ground that likely helps you.

 

I would half suggest a CLS filter, Astronomic do one. It in a way resembles a UHC filter but has wider pass bands so more light gets through from either end. The central portion of the spectrum is simply blocked about 540nm to 640nm is not passed. The intention being thaththat is where most LP is situated.

 

Color balance would change as the green area of the visual spectrum is blocked.

 

Could search other CLS filters in case a lesser cost one is around, maybe Svbony.


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#12 Dave Mitsky

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Posted 24 February 2020 - 01:11 PM

There's a section on urban astronomy (minus EAA) near the bottom of my post at https://www.cloudyni...mers/?p=5184287


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#13 Diomedes

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Posted 24 February 2020 - 01:19 PM

sweet, thanks Dave

There's a section on urban astronomy (minus EAA) near the bottom of my post at https://www.cloudyni...mers/?p=5184287



#14 spereira

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Posted 24 February 2020 - 01:28 PM

Folks, this is a friendly reminder that this forum is Beginners (NO ASTROPHOTOGRAPHY HERE).

There are separate forums on Cloudy Nights that handle all manner of astro-imaging, and EAA, for your continued enjoyment.

 

smp


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#15 JoshUrban

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Posted 24 February 2020 - 01:41 PM

thanks for the links, my next telescope is going to be a 8" Cat. My current one is a 70mm meade.  

You'll certainly enjoy that!  And hey, I haven't met a telescope I don't like, so enjoy the 70, too.  Any view of the sky is a good view!



#16 Tony Flanders

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Posted 24 February 2020 - 08:58 PM

In my experience, filters are either useless or counterproductive for viewing star clusters. But I can assure you that the view of M35 through an 8-inch telescope under heavy light pollution is vastly more satisfying that the view of M35 through a 70-mm telescope in identical conditions. Short of electronic assist, aperture and magnification are your best weapons against artificial skyglow.



#17 Volvonium

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Posted 25 February 2020 - 08:10 PM

Larger aperture will help with resolving point sources such as dim stars, globular clusters, moons, etc, but won't help in resolving nebula or galaxies.   With 16" under urban skies, I can get great views of planetary nebula and clusters, but light pollution defeats any and all ability to detect nebula and galaxies.    Night vision, EAA, and driving are the only option for those types of targets.  Fortunately, EAA is seeming to become much more affordable and accessible, without all of the waiting and post processing that is required of astrophotography. 

 

As far as I know, there are no filters that help with modern light pollution / led light.



#18 Tony Flanders

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Posted 26 February 2020 - 06:03 AM

Larger aperture will help with resolving point sources such as dim stars, globular clusters, moons, etc, but won't help in resolving nebula or galaxies.


No, I don't agree with that. No amount of aperture can fully compensate for light pollution where galaxies and nebulae are concerned -- nor where clusters and planetaries are concerned, either. For instance, I'm 100% sure that the view of M33 through a 4-inch scope under dark skies is far better than the view of M33 through your 16-incher from Long Beach in almost every way. However, the view through a 16-incher in Long Beach is still far better than the view through a 4-incher at that same location.

That's particularly relevant for galaxies with high surface brightness, such as M82 or M51. I'm sure that your 16-incher easily shows M82's two main dust lanes from Long Beach, and I doubt that's true of a 4-incher at the same location. At my astronomy club's observing field in the exurbs of Boston, MA, my 4-inch refractor shows M51 as two bright concentrations with nearly overlapping halos. But the club's 25-inch Dob makes the spiral arms quite obvious.



#19 Volvonium

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Posted 26 February 2020 - 07:41 PM

No, I don't agree with that. No amount of aperture can fully compensate for light pollution where galaxies and nebulae are concerned -- nor where clusters and planetaries are concerned, either. For instance, I'm 100% sure that the view of M33 through a 4-inch scope under dark skies is far better than the view of M33 through your 16-incher from Long Beach in almost every way. However, the view through a 16-incher in Long Beach is still far better than the view through a 4-incher at that same location.

That's particularly relevant for galaxies with high surface brightness, such as M82 or M51. I'm sure that your 16-incher easily shows M82's two main dust lanes from Long Beach, and I doubt that's true of a 4-incher at the same location. At my astronomy club's observing field in the exurbs of Boston, MA, my 4-inch refractor shows M51 as two bright concentrations with nearly overlapping halos. But the club's 25-inch Dob makes the spiral arms quite obvious.

 

Yes, full agreement; I think I must have worded it incorrectly for it to be misunderstood--

 

I've never been able to observe the majority of galaxies and diffuse nebula with my 16" under light pollution-- aperture did not help.  I went up in aperture solely for improved performance on globs and clusters. 

 

With the 16" under urban light pollution, M33 is completely invisible for me, albeit I suspect I might be able to detect something on exceptionally transparent nights.  I have to admit that I've not bothered to attempt M82 or M51 under my urban skies.  I've only been able to see M31 and M32 which are somewhat underwhelming and dissuaded me from trying other galaxy targets in a light polluted environment.



#20 lsintampa

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Posted 26 February 2020 - 08:13 PM

I've read somewhere (I don't recall where) that these type of filters don't do much for telescopes visual, but do better with AP cameras.




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