dose anyone use these regularly and know much about them?, im kinda curious cause i battle some light pollution, i usally just use a nd.03 filter to dull the glare but still theres quite alot of pollution, basicly id just like to know more about the ups and downs of pollution filters
A good LPR filter should suppress the light from neon and sodium lights and allow a clearer view of astronomical objects. Most of the better known brands achieve this. Available in 1 1/4", 2" or to screw onto the back of any SC system. Do a google search on LPR filters.
I have had the opportunity to own and try several light pollution filters. The general broadband filters like Orion SkyGlow (I owned one of this in the past) and Lumicon DeepSky are less useful for visual use but extremely useful for astrophotography. The narrow bandpass filters such as the Lumicon UHC (ultra high contrast), DGM Optics NPB (narrow passband filter), DGM Optics VHT (very high throughput, an in between filter between broadband and narrow passband) are better in this respect. I own all three of the mentioned. Other notable narrow pass band filters include Astronomiks UHC (John (Bambury) can chip in here) and Orion's UltraBlock. I have had some astonishing views of nebulae and they do make a lot of difference from cities and suburbs. I have also tried line filters such as the Astronomiks OIII (thanks Andrew...astro_south) and while these are great for planetary nebulas, they dim the views too much (unless you have a light bucket dob). If there was only one filter to get it would be a narrow passband filter.
I have an Astronomics CLS (light pollution filter) and is an improvement on Nebula over nothing but it does not seem to be as good as a full blown UHC filter (I compared briefly Ice's DGM to it at Kulunura).
The CLS is billed as a light pollution filter and was a bit less than 1/2 price of the UHC so I decided to take a punt...
Having now compared it to a "better" narrowband filter I'd say I would have been better off getting the Astronomics UHC (or others)...
It (the light pollution filter) is better than nothing but not as good as it could be IMO...if that makes sense
if i where to get one it would be for my 2" possl's, the thing is i am not sure at all which is for me? but yeah i do understand that phrase wavelandscott, i find that is true with most filters.
using a gso 12" f/5 with possls its quite of a light bucket most of the times. i like it tho, i think it would be really great with some kind of filterage.
The DGM NBP for little over $100 posted has got to be one of the best value ones around. It works great on nebulae, but no filter can substitute for dark skies.
I have only looked through a wideband filter once and from a fairly dark sky and saw a mild but noticeable improvement.
Whereas the narrowband ones are designed to filter out all but the wavelengths of certain excited gas molecules,and therefore designed for nebulae, could the wideband ones be of benefit for galaxy hunting?
In my area (20k Sth Canberra CBD) most if not all of the street lights are sodium lights. As I was troubled by light pollution I started off with an Astronomics CLS filter from Bintel. I was concerned that first night as I was staying in Paramatta and out of the hotel window the filter did not appear to cut out much light at all. mmmmmmmm Back home in Canberra, different story, it does help to some extent and depending on what I am looking at it can help. I have found the Baader Skyglow (Neodymium doped glass) filter to have a similar effect on reducing sodium light polution. UHC and OIII filters are much more agressive of course.
I have started using a 70mm F5 refractor as a travel scope. Last week I was at Tyabb airfield to the south of Melbourne. During the week I had a couple of opportunities for some brief observing sessions. I had taken a Baader Skyglow filter with me, the result ............. same as Sydney didn't help much at all.
