Light pollution filters

Hi all

Now that I, along with many others, have angered the weather gods by ordering new scopes, I've gone for the Zenithstar 80 myself, I know that the magnifications will be small and the field of view large, from my badly polluted backyard, magnitude 4 usually, 3 sometimes :roll: . I know that a good light pollution filter will be necessary, I see that Telescope-Service are selling a Baader UHC and this looks impressive. Does anyone out there have experience of this filter? Or are there others you can recommend?

One other thing. I observe with Meade Series 4000 Plossls, which I find excellent, they are 1.25" eyepieces, would 2" eyepieces work better with this scope? The scope is a 480mm focal length 80mm lens.

Thanks in advance for any help.

Paul

Paul --

Are you looking for a filter to make nebulae stand out better, or something to make the sky background more pleasingly dark? Narrowband filters (like the UHC) and line filters (OIII, Hα, Hβ, etc.) are more used for the former (and are often called "nebula filters").

But if you're looking for a darker background for low-mag views, I think you'd be better off with a broadband filter (something like the Lumicon DeepSky or Baader Moon & Skyglow). Keep in mind that none of these filters are a panacea when it comes to light pollution. They can help, but it won't be anything like getting out to a dark sky.

If you're looking for more in-depth info , I highly recommend David Knisely's article on CloudyNights:

www.cloudynights.com/item.php?item_id=63
Cheers,
-- Jeff.

Hi Jeff

Nice link, I guess that with the scope having such a wide field of view I would be looking for an improvement in the seeing of nebulae and the Baader UHC looks to be the better choice as it also has a dielectric coating for greater durability.

Thanks again

Paul

Paul,

I have two broadband filters and many several narrowband ones. Jeff is quite right in that your best all round bet is a broadband filter. I have a 1.25" parks optical filters and a 2" Astronomik CLS (minus city light) filter. Both are excellent, the Astronomik one is absolutely first rate and gives me views of galaxies that is not possible in the parks optical one because of its less discriminating blocking range. If you can afford it, I highly recommend the Astronomik CLS. I also heard the IDAS (hutech) filter is first rate too.

Paul,

I've tried a few LP filters in the past.

The IDAS filter is excellent for CCD or SLR but makes hardly any difference for visual. In fact Ron Wodaski uses this for many of his images.

I found the Orion Ultrablock good in the SCT but on my refractor it simply dims far too much of the image + it can't be used for photography at all.

Also used an Antares LPR & it works but turns everything a green/yellow colour.

The UHC filters are supposed to be great but I wonder would the 80mm aperture be simply too small to get a great effect?

Trev

Here is my opinion on light polution filters for observing (I know nothing abot imaging).

You can get broadband, narrowband and line filters.

I think the broadband are a waste of money as you get very little extra contrast for nebulaes and despite the manufacures claims i've never been able to see any improvements for galaxies.

Narrowband filters are a different story. They do nothing for galaxies, however when used on most other nebula objects they will impress you. I have a Meade 4000 Narrowband Filter that lets in Hydrogen Beta and Oxygen III. On my first outing I pointed scope at North American Nebula (which I have been unsuccessfully trying to view for years) and she jumped out of the sky............. removed the flter and she dissapeared.......amazing.

Narrowband filters will offer even better contrast, however you need different filters for different objects........ and they arn't cheap !

For an all round observing filter I would definately recommend a good narrowband filter.

Damon