Light pollution filter for a small refractor

[hunterknox]

Hi All,

Can anyone recommend a general light pollution filter for a short refractor (Megrez 72)? I'd want it for general widefield viewing with a 40mm eyepiece and it would need to be able to deal with the nasty orange sodium lights and the nasty white (mercury?) lights.

Thanks in advance,

Tom

[John]

I'm not sure about the filter but you could try using a shorter focal length eyepiece - the higher power will darken the sky background making DSO's easier to spot.

[TheThing]

For very few bucks, the Seben LP filter is a pretty good one (Seben = bad reflectors but good EPs, filters and refractors).

I picked one up 2nd hand for a tenner - well woth it!

[LukeSkywatcher]

I just bought one of these:

Light Pollution Reduction - Skywatcher Light Pollution Filter

Have not tested it yet. Cant go too far wrong for £20.........unless you get it cheaper,LOL.

[gataki]

Hi,

I use the Skywatcher LPF that Paul has linked to up there ^^^ on my baby refractor and my dslr. It's brilliant and makes a huge difference even under London's light polluted skies!

Liz

[ombos]

As above also, spot on.

[hunterknox]

Thanks folks. I'll go with the skywatcher then and see how I get on. Good to get a recommendation that's on the money!

[LukeSkywatcher]

I did a quick very scientific test the other night with the SWLPF. I held it up to my eye and looked at an orange street light. The orange glow from the light all but vanished.

[WayBig]

I have a 4.5inch reflector and got a skywatcher UHC filter from flo at christmas.

I went for a narrowband filter because i've a sports centre not that far away that very kindly floodlights a lot of the sky for me, in addition to the standard orange streetlights.

I've only really used it a few times on the orion nebula, it certainly darkens the background sky, improving contrast. Though it also darkens the nebula too (I think it transmits 95% of the good wavelengths), it's better once your night vision has kicked in properly, before then its a bit too dark in my scope with the filter.

I would expect this to be less of a problem in a larger aperture.

[John]

UHC (and OIII) narrowband filters are most effective on planetary nebulae I've found. They make some difference to other types of nebula although, as pointed out above, sometimes at the expense of the fainter parts of the object. Personally I prefer the unfiltered view on all DSO's other than planetary nebulae.

The Baader UHC-S filter is supposed to be effective even in smaller aperture scopes becuase it's band pass is a little wider than other UHC filters. I manged to spot the Veil Nebula with an 80mm short tube refractor when using an UHC-S which I felt quite pleased about

[WayBig]

The skywatcher UHC was £40 which I think is pretty good value, I think the skyglow broadband version is £20.

Used the UHC last night as a lunar filter (not ideal, but the best I've got at the moment) - the result, a fantastic emerald green moon