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LP Filters useful?

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#1 TheNosy1

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Posted 23 March 2013 - 05:19 PM

Is it worth investing in a good light pollution filter? How helpful are they towards reducing the effect of light pollution?

#2 mogur

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Posted 23 March 2013 - 06:09 PM

If you're talking about the broadband type filters my experience is that they reduce the overall light throughput, dimming the whole image. This makes them of little use for nebulae, which are pretty dim to begin with. I did find it somewhat useful on dim galaxies, but only for the core of the galaxy, not the whole object. If you mean narrow-band filters such as a UHC or O III, these are definitely useful as they do not dim the wavelength of nebulae but instead only dim the sky around it, making it stand out more against the background.

#3 GeneT

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Posted 23 March 2013 - 08:29 PM

Filters can help some, but for the most part, for the best viewing, get to the darkest skies possible.

#4 TheNosy1

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Posted 24 March 2013 - 08:40 AM

http://www.amazon.co...s00_i00?ie=U... I bought this a while ago and haven't received it yet. Is this a narrow band filter of just a filter which dims the whole image do you think?

#5 rinalmj

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Posted 27 March 2013 - 01:24 PM

I have 1.25" and 2" LP filters and have yet to notice any improved views as a result of using them. I have heard from others that their effectiveness is largely dependent on the type and amount of light pollution that you experience.

#6 David Knisely

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Posted 27 March 2013 - 09:38 PM

Is it worth investing in a good light pollution filter? How helpful are they towards reducing the effect of light pollution?


The broad-band LPR or "Light Pollution Reduction" filter can sometimes help provide a mild increase in contrast under skies that are fairly dark or when there is only a mild level of slight pollution, but not under moderate to severe skyglow. Even under darker skies, the improvement tends to be rather small when it is there. I note some improvement for reflection nebulosity and some of the larger more diffuse galaxies when using the broadbands under my home's ZLM 5.4 to 5.8 skies, but it isn't much. Once the skyglow gets strong enough, the broad-band filters lose much of their effectiveness. On emission and planetary nebulae however, the narrow-band and line nebula filters can offer a visible boost in contrast. For narrow-band nebula filters, I recommend the DGM Optics NPB filter, and for line nebula filters, I recommend the Lumicon OIII filter. For more information about filters, the following article may be of some use:

Light Pollution, Narrowband, and Line Nebula Filters

Clear skies to you.

#7 De Lorme

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Posted 28 March 2013 - 03:24 AM

Hi The Nose1, Check out the web site the Abbey Road{Jim
Thompson}. Great information! He uses the Hutech Idas LP-2 for visual.
The only problem though it cost $179 for the 1.25
De Lorme

#8 Illinois

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Posted 28 March 2013 - 06:15 AM

LP filters are okay but not great for light pollution. I have Orion Skyglow and Ultrablock filter. I dont see M8 Lagoon nebula in Chicago and I used a filter then I can see little faint nebula but thats about it. Not good for open clusters. O111 suppose be good for large telescope. Filter is more useful in dark sky like horsehead nebula, veal nebula, etc. I saw veal nebula in upper Michigan and I use filter that I can see improve detail and more shape of veal nebula.

#9 hfjacinto

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Posted 28 March 2013 - 09:13 AM

I've used a IDAS LP filter (which is really an imaging filter) and it helps a little, it seems to darken the sky enough to make galaxies more visible, but its subtle, like on M81/M82, they where visible without the LP filter, but with the LP filter, I saw a little more.

#10 orion61

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Posted 28 March 2013 - 09:57 AM

Filters are good for what each are intended.
Star clusters and Galaxies emit a broad spectrum of light which is not helped by LPR Filters.
I have found that under Light polluted skys a narrow band will help bring out emission Nebula, the whole picture LOOKS
darker but that is what the plan is to darken the background sky while leaving the Nebula's light the same.
If you don't think they work hold one up to your DVD/VCR while the lights are on! You will soon quickly see what colors get blocked.
Nothing will "Brighten" the objects but a bigger telescope!
The filters job is just to pass a certain part of the spectrum. That is why there are so many different ones.
I hope this helps clarify some things.
Another good trick is use a cloak over your head to block out stray light.. You will be amazed by the difference once you stop that light from the street light from sneaking in around the corner of your eye!!

#11 De Lorme

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Posted 28 March 2013 - 01:28 PM

Hfjacinto, Is the PL-2 affective on gobular clustors?
I have CR6" that I would be using this on. At the cost of
a $179{plus shipping} is it worth the money?
Thanks for the advice, Clear Skies, De Lorme

#12 hfjacinto

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Posted 28 March 2013 - 08:28 PM

Like I said it helps a little. M13 showed more stars but again it's subtle. The IDAS filter seems to darken the sky a tad more than the DSO.

As is it worth it, the effect is so minor I would tell you to get a c9.25 or c11 that will show you much more than an lp filter.

#13 De Lorme

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Posted 28 March 2013 - 09:19 PM

HFJACINTO, Thanks for sound advice. I'm looking into a bigger refractor. Clear Skies! De Lorme

#14 TheNosy1

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Posted 29 March 2013 - 05:05 AM

what do you mean by c11 and c9.25?

#15 hfjacinto

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Posted 29 March 2013 - 07:02 AM

A celestron 11" SCT or 9.25" SCT

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#16 De Lorme

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Posted 29 March 2013 - 08:42 AM

Would prefer a 8"F/6. I can handle the color. But if that
does not happen a C11. Or I would really think about selling
my CGEM and moving up to a CGEM-DX with a C14". But if I did
went that route it would be awhile. De Lorme

#17 Eric63

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Posted 30 March 2013 - 09:04 AM

I have three filters, the Moon and Sky glow, contrast booster and UHC. I find that the UHC makes a noticeable difference on Nebulae such as Orion or Lagoon. The M&SG did not make any difference, in fact I found that the addedd glass affected the view somewhat. I found the same thing with the contrast booster. I tried them both on galaxies, planets, from light polluted skies and from darker skies. Now I was using a 4" achromat and I read afterwards that they work best with larger apertures.

Eric

#18 TheNosy1

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Posted 30 March 2013 - 11:04 AM

Thank you very much, were you using a Televue UHC?

#19 Eric63

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Posted 30 March 2013 - 11:55 AM

I'm using the Orion 2" Ultrablock UHC.

Eric

#20 TheNosy1

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Posted 30 March 2013 - 12:09 PM

Thank you.

#21 De Lorme

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Posted 08 April 2013 - 10:59 PM

In the refractor forum under"Baader Fringe Killer or Apo?" John said that he's been experimenting with the
Astro Hutech Idas LPS2 filter for visual and he liked it. But he didn't go into any real detail.
When I was searching whether to us baffles,flocking or both
in a refractor tube I came across a guy {I cannot remember} who showed pictures of his refractor tube before
and after he flocked it. It was like night and day. He said
that flocking gave it 25% to 30% more contrast. He went on to say that he occassionly uses his lpf now.
Also, I've read that the Orthos will help with the contrast.
Because of their high polished glass,3 to 4 elements and
narrow field of view.
I'm believing that doing all three will make a real differance in looking at gobular clusters under our light polluted skies. Clear Skies, De Lorme






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