Light polution filters, UHC filters, OIII filters, ahhhh!

[Tlawrence84]

Sorry for posting something that may have been covered several times, but searching for "Filters" returns so many results it's hard to find what I'm looking for.

I bought a telescope, without really considering light polution until I got home (have we all been there?) after doing quite a bit of reading, it seems like some of the filters are not quite what they claim. I only really have my back garden to view from, which is fairly small so it gains light polution from all around where the other houses are. Although I can turn off MY living room lights, I cant ask my neighbours to do the same! Is this just a poo position to view from, or will filters help?

Out the front of my house, it will result in street lamps glaring straight into the scope, so I think this is really out of the question as it will be hard to dark adjust my eyes.

Galaxies, Planets and Nebula are what I am most interested in, so immediately I am taken to the Skywatcher UHC filter to improve views of nebula. I understand these limit light to only let through wavebands that nebula emit.

Is there a magic galaxy filter, or light polution filter that will allow me to view details on Galaxies? My only view so far has been the andromeda galaxy, and this just looked like a thumb print on the lens, but my scope was angled almost at a neighbours window when they had the light on! (due to the angle in my garden, I have limited viewing angles).

Skywatcher have a light polution filter, but from reading on this forum, it seems to be a bit of a gamble as to whether it really makes any improvements, so it's a buy it and see what happens? It will probably come in useful when I go camping in the future I suppose, as sites now tend to use old style orange street lamps.

[John]

As you say, UHC and O-III filters only improve the contrast of nebulae. For galaxies really dark skies are what you need. There is no "magic bullet" filter for them.

[RikM]

One thing that will help is try and shield your eyes from the lights. If your eyes can't fully dark adapt, you are not going to get the best views no matter what filter you use. I normally wear a hoody top when observing.

I find a UHC a useful filter to have for making the nebulae stand out a bit better.

I have a skywatcher light pollution filter, but it doesn't seem to do much visually (is very good at combating light pollution for imaging though). I use it for enhancing detail when viewing the moon and planets, rather than combating light pollution.

[NGC 1502]

Hi, I'm also in Southend, about 0.5 m north of the town centre, so very light polluted. Most of my observing is done from my back garden.

There are lots of opinions about light pollution filters, but there is no magic bullet that will improve views of galaxies (in my own opinion, for what it's worth)

I have UHC and an O111 filters, they do help, but only with specific objects, like M27, M98 and the Veil nebula. The Veil is totally invisible from my back garden without a filter, but on a moonless night in the autumn, can be seen unmistakably.

However, nothing beats getting to a better and less light polluted site, that will improve views of galaxies etc without doubt.

I'm on good terms with my neighbours, they draw curtains when I ask, that helps a lot. I feed their cat when they are away, it's a good trade...........

But please don't think that you can't do enjoyable visual astronomy from Southend, because you can.

I do observe all classes of objects from home, but tend to view the moon, planets and double stars the most, they are affected by light pollution far less.

Regards, Ed.

[Moonshane]

viewing with street lights visible to your eyes is almost impossible. as you say you'll never get anywhere close to dark adapted. it's even tricky if you live near any other people (i.e. almost all of us) as bedroom, bathroom, insecurity, and lounge lights all get turned on constantly until people go to bed and even then.......

I have a few filters all two inch other than the Baader Solar Continuum and here's my take on them:

1. light pollution - I have a Baader Neodymium - don't use it for light pollution (though I have lots) as I use higher magnidication when required to darken the sky. I use it for lunar (I don't get on with moon filters) and planetary observing (Jupiter and Mars mainly)
   
2. UHC - I have a Castell UHC - very useful as a general filter and simply spectacular on the Orion Nebula. I use it less then the Oiii but might be different if I had a smaller scope only. I see the UHC as making those objects already apparent slightly better
   
3. Oiii - again Castell - really striking results on the appropriate objects - I see this as making invisible objects visible, hence I'd recommend this over the UHC personally.
   
4. Hb - a little bit specialist - not even had chance to use it but got the Skywatcher one for £40. hopefully will reveal the Horsehead in my 16" scope if I ever see Orion again this year with no moon. buy this last
   
5. Baader solar film / Solar Continuum combo - the solar continuum filter must only be used with a proper solar film filter or Herschel wedge - on its own it gives no protection - don't need the Baader SC filter really but it gives more contrast to the solar disc, revealing more granulation/fasculae detail.
   

I'd say get 1. then 3. then 5. then 2. and then 4. but if you just buy two then 1./ 3.

[Tlawrence84]

Thanks for all the useful posts. I certainly haven't given up on observing from my garden, but just after something that could help me see some detail. Might get the UHC, given that I have a smaller (130mm) scope, and try get to some darker sites to see what the scope can really do before I spend more money.

I might consider a moon filter rather than the light polution one then, at least I can check out the moon when it's out on full show and not feel like I'm observing a light bulb!

[jason.p]

I know it doesn't solve the general background LP problem, but I've screened off a couple of annoying streetlights with a blanket hanging over a strategically placed extra washing line.

[cotterless45]

If you've got streetlights shining through your scope or affecting your property , I'd ask the local authority, usually the county council to get them shielded.

The purpose of streetlights is to light up the footway and highway and not your property.

I have 9 streetlights around here, by use of a couple of fence panels and some pld blankets on poles, I can get away from their distant glare.Even light bouncing off buildings will affect your dim adjusted eyes.

You'll also find that using higher magnification will blast through bad sky. Try x50 and up to x100 for faint galaxies.

Hopefully your local authority will have a scheme in mind to switch off street lights from midnight until 5am to save money, if not ask them how much it's costing to light up your garden ,

Nick.

[emadmoussa]

I second the ''shielding your eyes''. I have a problem with the street lamp at the bottom of our garden (I've been in contact with the Council, and hopefully they'll paint it to to deflect the light away from the garden), so basically whenever I'm looking into the telescope eyepiece I usually put a towel on top of my head and the focuser. This helps adapt your eyes more comfortably to the light. You should be able to see more stuff then.

[Moonshane]

here's what I did

http://stargazerslounge.com/topic/113007-observing-screen/