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Do £20 Light Pollution Filters Work?

Dark Amender

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Dark Amender

Dark Amender

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Do £20 Light Pollution Filters Work? I am thinking of buying one because of the stupid amounts of Light Pollution in Oldham. would it really make a difference or is it a waste of money? Would it make the Andromeda Galaxy look like a galaxy, and not the faintest ever small blob? Also i have some 10x50 binoculars they can see blue clouds of the Orion Nebula but with my telescope all i can see it the 2 stars... would it help with that? and will i ever be able to get the Horse Head Nebula with the stupid amounts of LP in Oldham?

Thanks,

Dark Amender

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Moonshane

Moonshane

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hi guys

I am no expert but filters are quite specific things and I have a cheap LP filter which really does not a lot (I live in Stockport). the best recommendations I have had are for Astronimik or Lumicon filters (the UHC and the Oiii filters) which are about £100 new and if you are lucky about £50-70 used at 1.25".

as for the Horsehead, this is difficult with a large instrument (maybe 10-12") and the right filter (Ha filter - also about £100 new) with our skies I fear.

with any scope and no filters you should be able to see good detail/extended plumes of 'smoke' on the Orion nebula and probably the four stars in the trapezium. with my dob and 18mm eyepiece it goes on 'forever'.

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Wurzil

Wurzil

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I think the cheapy skywatcher LP filters mainly filter out light pollution from the old orange "sodium" streetlights. Most councils around the country seem to be replacing these with the new type of streetlights (the white/pinkish ones) thus making those light pollution filters less effective. What sort of streetlights do you have in your area?

I think FLO let you return a filter and get a refund if it turns out to be no use to you (of course youll have to pay postage back) so it might be worth a try anyway.

I bought an LP filter a few weeks ago and it doesnt seem to do very much except when im looking very close to the horizon where the LP is worst. Some people say they see a great improvement though.

hope this helps

warren

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Demonperformer

Demonperformer

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My [admittedly limited] experience, for what it's worth:

I have a celestron LPR filter. This turns M57 from the faintest haze that is not really recognizable to a clear ring with a distinct gap in the middle. This is from my front garden where I am surrounded by orange streetlights. This is an extract from the observing report I did at the time:

Low in the northwest by this time was Vega, so I decided to try my luck. Have never had any joy seeking out M57 from my front garden, but with the LPR filter it was clearly visible. Having enjoyed the view for a while, I decided to remove the filter and see if I could still see it. There was a faint hazy patch where I knew it to be, so in one sense I can say I saw it without the filter. In reality, if I had not been looking at it moments before, I would have dismissed that patch as nothing worth mentioning.

The biggest surprise though was when I attached my UHC filter – something that I understand is designed specifically for this sort of object. It blacked out everything except the two brightest stars in the fov and of M57 itself, there was not even the ‘there might be something there’ glimpse that I got with no filter. Another one of those ‘I really don’t understand it at all’ moments. Maybe someone out there does? Anyway, back to the LPR for another look at M57. Nice.

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Moonshane

Moonshane

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next time I am out, I'll undertake a better more objective test on the LP filter I have. I am sometimes a bit lazy and cannot be bothered changing filters over all the time.

I recall that I could quite clearly see the Ring Nebula with my refractor (didn't have the dob then) and no filter so maybe the LP is not that bad where I live hence the reduced effectiveness for me?

I'll report back after my next outing - when (if) the skies ever clear!

DP's comments are interesting especially re the UHC filter.

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Brendan of Borg

Brendan of Borg

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I bought the £20 LP filter from FLO and yes, it does work for me! Early evening test was simply to look through the filter directly at the street light and have to say, a reduction of probably 75% - and thats direct viewing! The lights are obviously the right ones for the filter but yeah, I was unsure at time of purchase!

If you can get a refund if no good, I would go for it!! (I'd check up on that first though!) ;)

Very fast dispatch too btw!

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LukeSkywatcher

LukeSkywatcher

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I bought one of the £20 SW LP filters from FLO and i have to say its works GREAT. I can aim my scope right between 2 street lights and see so many stars and the sky is dark. Thankfully i dont have to observe under these conditions (this was an extreme road test of the filter). In my back garden (no direct light from streetlights) it works amazingly. The same filter even works better as a moon filter then the dedicated moon filter i have.

Honestly for £20..........................you can not go wrong.

I'm now on the hunt for a LP filter for my Canon 450D.

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LukeSkywatcher

LukeSkywatcher

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I bought the £20 LP filter from FLO and yes, it does work for me! Early evening test was simply to look through the filter directly at the street light and have to say, a reduction of probably 75% - and thats direct viewing! The lights are obviously the right ones for the filter but yeah, I was unsure at time of purchase!

If you can get a refund if no good, I would go for it!! (I'd check up on that first though!) ;)

Very fast dispatch too btw!

I did the same direct eyeball viewing test and i concluded that it reduced the glow by about 85-90%.

I also didnt know if i was buying the correct filter and FLO said that if i find it useless that they would refund my money (and i send it back to them).

Well worth the money

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LukeSkywatcher

LukeSkywatcher

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i am interested in this too, if i got 1 would it give me a better view of nebula

Simple answer is NO. LP filters are designed to block/transmit certain light wavelenghts. Nebula filters are designed to block/transmit different light wavelenghts.

A LP filter DOES improve the situation slightly when observing nebulae............it reduces the skyglow from streetlights but it doesnt improve contrast etc of actual light from the nebula.

With my LP filter on my EP,M42 (Orion nebula) does look a bit better because the standard LP in my area is being blocked which makes the nebula look a bit brighter. But to observe nebs you really need a dedicated nebula filter.

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LukeSkywatcher

LukeSkywatcher

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lol this all all kinda confusing but hey... im a noob... so is it woth £20 or is it a load of rubish? is there something better i could get for £20 ?

For £20....................this will be the best £20 you ever spend. Its a LP filter though and NOT a nebula filter. It works GREAT as a moon filter also so you kill 2 birds with 1 stone.

Go for it.

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Whippy

Whippy

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I think it's worth pointing out a couple of things here.

General LP filters such as the Skywatcher model, Astronomik CLS and the Baader Neodymium attempt to cut out general light pollution whilst trying to keep light from celestial objects. Problem is that certain sources of light operate at the same frequencies as the ones coming from celestial objects and in some cases you'll either lose some light from the object you're looking at or still have some LP at the eyepiece. It really does depend on your location and what lights are around you. FWIW, I did a review of three LP filters some time ago and found none of them worked for me as they cut out too much light from the object I was observing.

UHC & OIII filters are classed as 'nebula' filters because in the main, nebulae emit light at certain frequencies so manufacturers are able to make these particular filters only pass light at those frequencies. These make them great for nebulae (obviously!) but for star-light based objects such as clusters and galaxies they're no good.

BTW, if you want the best chance of observing the horsehead nebula it's a H-Beta (Hb) filter that'll do the job and a very big scope as it's a real challenge!

HTH

Tony..

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LukeSkywatcher

LukeSkywatcher

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The success of a light pollution reduction filter depends greatly on how well it matches your particular light pollution. If it does then the results will be magnificent, if not you will wonder what all the fuss is about. A good retailer should understand that and not quibble when/if you choose to return it for a refund.

Steve

That's what you guys at FLO said to me when i bought my LP filter.

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Moonshane

Moonshane

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maybe I bought the wrong one - off Ebay a while back - silly me!

just using my eyes I can see it makes a difference so presumably will at the scope. will give it a try out next time. Steve, would the Baader version be worth the extra?

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FLO

FLO

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Steve, would the Baader version be worth the extra?

Only if it works. The only way to find out is to try it and see. The latest Baader Neodymium does include UV/IR cut so is better suited for imaging.

HTH

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