Light Pollution Filter

[JDWolf]

This past week I've been on holiday in a little village called Docking near the Wash. So armed with a 8" newt and no street lights i spent some time looking for some fuzzies. Managed to find a load of fuzzies that i would never see in my lovely light polluted skys near my house, M51 is simply breathtaking! Easily my favourite fuzzie so far.

Anyway so now I'm back home and have lovely street lights and a lot less fuzzies! So with my birthday coming up I'm thinking about getting a light pollution filter, what do you guys think about them? If i get one will i be able to see M51 in my lovely light polluted back garden? Also is there any real difference between the different make? and if so which one would you recommend?

[GordonCopestake]

First make sure your street lights are yellow sodium lights, it seems the new fad of councils to replace street lights with new broadband white magnesium lights which are almost impossible to filter out.

If your lucky enough to have only sodium lights around your observing area i can recommend the baader moon and skyglow filter. SCS sell them for £50 for the 2" version. There are many other LPR filters however but this is the one i have so i cant recommend others.

[Kaptain Klevtsov]

I have 2 of these, the CLS and a Nebula filter. The CLS seems to work better for imaging, but I've not tried it visually yet. The nebula (ALP from scopes'n'skies) just makes things darker visually and for imaging.

There is also the neodymium filter which is often cheaper, this has had good reviews here.

I think that the biggest problem with street light pollution (where I am anyway) is that your eyes don't open up fully as it isn't dark enough. The filter gets you half way there though.

Captain Chaos

[FLO]

Just to clarify:

The Baader Moon & Skyglow and the Neodymium is the same filter. James wrote a review a while back; heres a link:

http://stargazerslounge.co.uk/index.php?topic=2527.0

[JDWolf]

Thanks for the replies, yep i just have yellow sodium lights near me and i don't think my local council has any plans to change them.

So do any of them actually allow you to see fuzzies that you would normally be covered by the light pollution?

The Baader Moon & Skyglow filter seems good for knocking out the light pollution (http://www.scsastro.co.uk/it100005.htm) and is not too bad a price either. The ALP is more expsenvise (http://www.scopesnskies.com/prod/34.html), does it offer anything more for the greater price? Anyone used / heard about these : http://www.rothervalleyoptics.co.uk/detail.php?id=907 http://www.rothervalleyoptics.co.uk/detail.php?id=1364 http://www.rothervalleyoptics.co.uk/detail.php?id=551

I guess there is no substitute for dark skies but i what to try and improve the amount of fuzzies i can see in my back garden.

Thanks for all your help

[Albireo380]

I have an AStronomik CLS filter and it certainly reduces the light pollution. But everything has a blue caste to it.

If you want to do some imaging, you can get a Borg (Hutech) light pollution filter. The are specially made to keep the colour balance the same as just looking without a filter. SCS Astro sell them. They are hideously expensive, but a dedicated imager I know swears ny them.

Tom

[Albireo380]

I have an AStronomik CLS filter and it certainly reduces the light pollution. But everything has a blue caste to it.

If you want to do some imaging, you can get a Borg (Hutech) light pollution filter. The are specially made to keep the colour balance the same as just looking without a filter. SCS Astro sell them. They are hideously expensive, but a dedicated imager I know swears by them.

Tom

[Guest MoJo]

First make sure your street lights are yellow sodium lights, it seems the new fad of councils to replace street lights with new broadband white magnesium lights which are almost impossible to filter out.

Oh dear. My house is surrounded by them. And yes they are very bright even from the middle of a field 400+yds away. Looking south OK ish then turned north and they HURT my eyes they were that intense!

Damn LP (Hmm this could be turning into a signature!)

MoJo.

[JDWolf]

Thanks for the advice, think i will see how much i get for me birthday and then decide on which one to get.

[Ant]

Just one thing to note...

The CLS filter I had was VERY good - but images that I took needed more than double the exposure time to get to the same point. So for visual obersing I think IMO that the Moon and Sky Glow one may be better for you.

TBH I didn't think that there was much between them, I guess it depends how bad the LP is. The Moon and Sky glow filter works well up to about 3 - 4 minutes exposure - but after that it isn't so good. But the CLS goes on for ages...

Ant

[JDWolf]

Seen as i would like to get into photography soon i think the CLS sounds like the better out of the too. Where did you guys buy your CLS from? Anyone know where i can get a good deal on one?

[MartinB]

don't know about a good deal but I got mine from Bernard at Modern Astronomy

[JDWolf]

Just thought I would post this as a follow up to all my questions last month about light pollution filters. I emailed Bernard @ Modern Astronomy regarding light pollution filters. This is what he sent back and it pretty much know which filter I’m going to get now. Just got to wait for my birthday

The CLS is about the best broadband filter out there meaning it tries to let through as much of the spectrum as possible and cuts out standard Sodium, Mercury and air glow light. On the other hand a normal UHC filter is designed to be narrow band and to let through only the emission lines from nebulae. The Baader UHC-S is actually somewhere in the middle of the classifications as it lets through more of the spectrum than a normal UHC filter but less than a standard light pollution filter. Astronomik now have a similar filter called the UHC-E

Visually the UHC-S and UHC-E would be of use for general observing in heavily light polluted areas or with smaller scopes, say less than 6”. In places with average light pollution or with larger scopes you’re probably better off with a “real” UHC filter like the Astronomik UHC as it will reveal more detail in nebulae due to the narrower band pass.

The CLS doesn’t produce dramatic effects to the eye (except when you look at a sodium lamp with it!) but it does enhance general imaging dramatically.

My advice is to get the Astronomik UHC for visual work if your scope is over 6” in aperture for looking at nebulae in particular and the UHC-S or UHC-E if its less than 6”.

I suggest you only get the CLS when you come to do long exposure imaging.

We have the Astronomik UHC, CLS and UHC-E in stock and will have the Baader UHC-S in a couple of days.

Prices are:

Astronomik UHC £69

Astronomik UHC-E £49

Astronomik CLS £49

Baader UHC-S £49

Prices include delivery and VAT.

Please let me know if you need more info as this topic can be confusing

Regards

Bernard

Modern Astronomy

[FLO]

Thanks for the update Jon