LP or UHC Filter?

[Bones88s]

Hi guys, I'm a beginner whose recently purchased a Celestron Nexstar 8SE for viewing DSO. However due to the light pollution here in Manchester I'm struggling to see anything above a light blur and cannot make out M13 at all and therefore I was thinking of purchasing a Light Pollution or UHC filter.

Would I need to buy both or will the UHC also reduce a lot of street light etc?

Also, looking at prices on Amazon UHC filter seem to start around £40 then go up with some of the filters around £70 advising they are for a larger apertures. Is the Nexstar 8SE considered a larger or medium aperture scope?

Thanks in advance and clear skies people!

Ste

[wxsatuser]

Bought this for LP.....expensive, hoping it's as good as advertised.

http://www.firstlightoptics.com/light-pollution-reduction-imaging/hutech-idas-p2-light-pollution-suppression-filter.html

[swamp thing]

Hi

Be advised, the UHC will improve the views emission nebulae only. It won't help your views of M13 and other globs.

Stars emit light right accross the spectrum so are filtered out by narrow band filters like the UHC. This is why filters cannot help with star clusters and Galaxies. Travelling to darker skies is the only way to gain better views of them.

[rwilkey]

Bought this for LP.....expensive, hoping it's as good as advertised.

http://www.firstligh...ion-filter.html

This filter it seems is for photography, it will be interesting to see if it performs for visual use as well? The best 'all-round' multi purpose LP filter is I believe the Baader Neodymium filter: http://www.firstlightoptics.com/light-pollution-reduction/baader-neodymium-filter.html

UHC and OIII filters are for bringing out nebs and do not help with globular clusters.

[Zuben Elgenubi]

Hello Ste, when you say you can't see M13 at all do you mean it is very faint or there is literally nothing there?

If there is nothing there, are you sure that the scope is properly aligned/focussed/set up? M13 is a fairly bright DSO - I observe from a light polluted site (though probably not as bad as Manchester) and M13 is pretty easy to spot with my 200p.

I am a relative beginner myself and if I'm wrong I'm sure someone will set me straight, but I would expect that with your scope you should be able to see something of M13 even with fairly bad light pollution. Fainter DSOs may well be more of a problem.

Gareth

[rwilkey]

Ste, the 8SE is a medium telescope, but don't believe all that the manufacturers say about the limits of filters, the OIII is said not to be used in 8" or under scopes, however, they work well in most apertures, large or small, as does the UHC filter - however, there is no substitute for dark skies.

[michael.h.f.wilkinson]

I have a Celestron GP-C8, which has essentially the same optics as your scope, and found an LP filter (Celestron) useful even on galaxies, as long as the LP was mainly from low-pressure sodium lamps or mercury lamps. These produce mainly line spectra, which are blocked quite well by the filter. I have a UHC filter and an O-III filter as well. Both help a lot on emission nebulae. The nice thing of the SCT design is that you can easily take it along in even a small car, and drive to a really dark place. There is indeed no substitute for that.

[Bones88s]

Thanks for the info everyone. So just to recap, the filters probably won't help viewing clusters and Galaxies but should reduce the LP, so should I just but the UHC filter for LP reduction as well?

@Gareth, I maybe doing something wrong finding M13 however I've used the tracking on the scope which locates Andromeda and the Double Cluster ok... I will try again on the next clear night.

[Bhm2344]

I brought a CLS filter for my camera, they also do one for your 1.25 or 2 inch (www.365astronomy.com/astronomik-cls-visual-deep-sky-light-pollution-filter-125in-p-2180.html) it may be worth a look at so to speak. They are no so aggressive as a UHC filter apparently.

[TwoPi]

Thanks for the info everyone. So just to recap, the filters probably won't help viewing clusters and Galaxies but should reduce the LP, so should I just but the UHC filter for LP reduction as well?

@Gareth, I maybe doing something wrong finding M13 however I've used the tracking on the scope which locates Andromeda and the Double Cluster ok... I will try again on the next clear night.

IMO filters are a bit of a minefield, because different manufacturer's filters of the same type have quite different characteristics. I have mild light pollution (some high pressure sodium streetlights near me, obviously nothing on the scale of Manchester) and find that my Astronomik UHC filter does block most of this out, and it is as I understand it, it is one of the more 'generous' examples of a UHC filter (i.e. it lets a relatively wide band of wavelengths through). So UHC filters in general will probably help filter some LP out and should increase the contrast of nebulae (but as everyone else has pointed out, don't help with galaxies / faint stars / clusters etc.). All that said, whether they will filter enough out for your location (given the massive mix of polluting light sources in a city), I'm not sure.

I found this sitequite useful, it's a bit overwhelming at first but it shows wavelength comparisons of different types of filters, including (at the bottom of the page) how high pressure sodium lights are affected by some of the filters.

Bottom line is it pays to not just think about which category of filter you want, but also which manufacturer would suit your needs best.

Hope this helps.

[rory]

if you've these modern white street lights about your area then a lp filter wont be any use. the uhc is handy for emission nebula though. my limited personal experience lead me to preffer unfiltered views where possible and trying to get to a darker location. the lumicon uhc did however really show the veil nebula to me which would otherwise be invisible.

[Stargazing Glaswegian Gaza]

Hi Ste, You should go for the Baader Neodymium Filter, i took R wilkey's advice and it certainly makes the skie a lot darker and I found it made a notable difference. I noticed a lot more stars in clusters that were not there before i had the filter for sure!! Well worth the money.

[LukeSkywatcher]

Thanks for the info everyone. So just to recap, the filters probably won't help viewing clusters and Galaxies but should reduce the LP, so should I just but the UHC filter for LP reduction as well?

@Gareth, I maybe doing something wrong finding M13 however I've used the tracking on the scope which locates Andromeda and the Double Cluster ok... I will try again on the next clear night.

A LP filter and a UHC filter are two different beasts. A LP filter will eliminate light waves from those horrible orange street lights. A UHC filter eliminates certain light waves from certain type of nebulea (Orion Neb etc). You really cant use a UHC filter as a LP filter as it works differently.

LP filters darken the sky and get rid of the orange glow.

UHC filters make certain types of naked eye nebs look even better.

OIII filters make a certain type of neb not visible to the naked eye,visible (Rosette, Veil), etc.

Hope this helps.

Personally i feel the need to own one of each.

Paul

P.S.~~~to view galaxies, you really DO need to observe from dark skies. Otherwise they just appear as non-descript faint fuzzied.

[Bones88s]

Well I've just brought a LP filter as this seemed the cheapest option to get first. Thanks for the advice & he's to clear skies so I can try it out...

[Moonshane]

hi mate

my sister lives in Denton and the LP is pretty bad. that said, I'd still expect you to see M13 OK if you can see the double cluster and M31.

if you like, send me a PM and maybe you could try some of my filters and in return I can look through a SCT for the first time. they are 2" filters though so bear this in mind.

I have found a spot I might try near Marple which seems pretty good with a decent south view and not much nearby.

it's worth traveling a little bit.

cheers

Shane