Filters - are they worth it?

[JTmunmun]

Just wondering what the title says. I am specifically looking at the Lumicon DeepSky as it seems a pretty good all-around filter for an affordable price - if it works. I am currently just doing visual, and hoping for any assistance in seeing nebulae in the light polluted area I live in. I don't expect a filter to be a magic fix, but anything helps. Is it worth the cost for this? I may also get around to astrophotography in due time so even if it is negligible for visual but helpful for AP, that would be worth it to me. If that specific Lumicon one is not all that great do you have any other recommendations for a decent filter for nebulae viewing in light pollution in same price range? I have seen some posts where people say the Lumicon UHC is actually better than the DeepSky. Anyone with experience with either? TYIA.

[John]

It depends on the scope you are using but my experience is that the UHC and O-III filters (by Lumicon, Astronomik or other brands) do make a difference when viewing nebulae, even under light polluted conditions. They work even better under dark skies of course but we can't all have those !

The broadband filters such as the Lumicon Deep Sky do make some difference but the UHC and O-III types are much more significant, in my opinion.

Here is a report worth reading:

http://www.prairieastronomyclub.org/useful-filters-for-viewing-deep-sky-objects/

[jetstream]

1 hour ago, JTmunmun said:

Just wondering what the title says. I am specifically looking at the Lumicon DeepSky as it seems a pretty good all-around filter for an affordable price - if it works. I am currently just doing visual, and hoping for any assistance in seeing nebulae in the light polluted area I live in. I don't expect a filter to be a magic fix, but anything helps. Is it worth the cost for this? I may also get around to astrophotography in due time so even if it is negligible for visual but helpful for AP, that would be worth it to me. If that specific Lumicon one is not all that great do you have any other recommendations for a decent filter for nebulae viewing in light pollution in same price range? I have seen some posts where people say the Lumicon UHC is actually better than the DeepSky. Anyone with experience with either? TYIA.

 

46 minutes ago, John said:

It depends on the scope you are using but my experience is that the UHC and O-III filters (by Lumicon, Astronomik or other brands) do make a difference when viewing nebulae, even under light polluted conditions. They work even better under dark skies of course but we can't all have those !

The broadband filters such as the Lumicon Deep Sky do make some difference but the UHC and O-III types are much more significant, in my opinion.

Here is a report worth reading:

http://www.prairieastronomyclub.org/useful-filters-for-viewing-deep-sky-objects/

JT mun mun, heed the word of John above ^^

IMHO.

[Dave In Vermont]

I concur with the above. And do encourage you to read through the paper John linked above by David Knisely from the Prairie Astronomy Club. Another excellent paper by David Knisely is this one:

http://www.prairieastronomyclub.org/filter-performance-comparisons-for-some-common-nebulae/

It will help you find the best filter to use on many, many different DSO's you're likely to be finding in the near future. Having a copy of the above paper on hand is a good asset. You'll likely be turning to it again and again. To this point, I've created a Pdf. of it for downloading to a computer and filing it for easy reference. Here you go:

Filter Performance Comparisons For Some Common Nebulae - by Dave Knisely.pdf

A question you'll likely have is which filter should you get first - a UHC or a OIII? My answer to this is to toss-a-coin. It's a very tough call. A third narrowband-filter type is the Hydrogen-beta - or Hb - which is useful for quite a few different DSO's. But it's much more rare, so I'd let it wait for a later day. Now regards the UHC & OIII-filters, something to consider is which brand should you buy? With narrowband-filters, a "bargain" isn't necessarily a good guide to shopping! Knowing you are planning on visual use for now helps to narrow the field of good choices for these filters. You want one that will allow you to see the most detail in the chosen DSO and not darken them. I'd suggest, from personal experience and of others I've known and conversed with, either Astronomik or Lumicon for these. Not cheap - but 'cheap' here translates to basically useless. Beware.

A good narrowband-filter is a long-term investment, and with proper care, last a lifetime. So don't sweat the money - this should be a one-time expenditure. Just be sure to keep them in their case and in a safe place when not in use.

Happy Hunting!

Dave

[pjsmith_6198]

Yes, heed John's advice.   It is excellent.    From my experience in observing in a red zone, broad band filters help somewhat but the narrow band UHC and OIII filters are much more useful.   These filters can make a difference between seeing and not seeing an object.   Where I observe, M97, Veil Nebula, Helix nebula are completely invisible without them.   Think of these as nebula filters and not LP filters as they will not work for galaxies or star clusters. (Although they can be used to see nebula regions in the some galaxies such as M101, M33, M31. )       I would get either a UHC or OIII filter first.   I tend to use my OIII filter most ,but I think other people get more mileage from the UHC.   

Phil

[JTmunmun]

Thanks for the excellent advice. I knew you guys would have helpful answers. I'm glad I didn't buy the DeepSky on a whim! Looking like the UHC might be the winner to me.

[ronin]

I would make sure that the filter you purchase actually does what you expect it to.

Some UHC filters pass OIII and Ha, others pass OIII only, in which case you may as well purchase an OIII filter. Makes it all a little more complex concerning choice. I tend to check the transmission of filters from the data here: http://www.astrosurf.com/buil/filters/curves.htm

It assumes that the filter in question is covered, but the usual suspects are.

I do recall that it has been said that if you had to purchase one filter alone then the single best item is an OIII filter. Whether or not that is correct I cannot say as at this time and after many years I still do not own a filter. Maybe one day but none so far.

[Dave In Vermont]

My suggestions of either Astronomik or Lumicon are, as stated, based on experience and others experiences. I didn't wish to get too technical with JTmunmun, Ronin, but I also factored-in the transmission-graphs on these (and other) filters.

Such as:

 

 

And.....

 

 

While the Lumicon OIII does allow for more Hb and Ha through, I'd hardly say this constitutes a reason to not get a dedicated UHC-filter, too.

I rest my case,

Dave

[JTmunmun]

As I understand, OIII and UHC are pretty much only going to help with nebulae, and do pretty much nothing for galaxies. I read through that article and it said the broadband filters (like DeepSky) would help a little bit with galaxy viewing. As it stands, in my location I can pick up a few galaxies, albeit very faintly and just the center - Bodes, Sombrero, Blackeye. Do these broadband filters actually do anything worthy of their cost to help with galaxy viewing in your experience? I have looked those up and it seems some like them, some say they do nothing. I know a dark sky is pretty much the only real solution though, but I am definitely open to getting a UHC/OIII and broadband if it will help.

[Alfian]

A Good thread and some useful links that I've bookmarked, thanks guys.

[John]

They say that the best investment to get great galaxy views is some fuel in your tank to take you and the scope to a dark sky site

That said, my backyard has some light pollution issues but I've still managed to see many galaxies down to around magnitude 13.8 with my 12" scope. I've not found a filter of any sort that improved the views of galaxies though, despite trying broadband / light pollution types. I found that I sold these on rather quickly wheras the UHC and O-III type have proved very valuable for nebulae.

[ronin]

Yes they only really help, or help most significantly, on nebula as these tend to fall into being "strong" in either Ha or OIII, will depend on what was created when the star went nova and the nature therefore of the emissions. So you filter to allow this strong one through and block the remainder, and hence increase the contrast. All gets complicated as you really first need to find the spectral emissions you will get. Which is often done by syicking a filter in and seeing what effect it has.

Strange maybe but we seem toi have little talk of images and spectra at the S lines.

Galaxies being "white" are not strong at one specific wavelength. So a dark sky is the best. People use an Ha filter on galaxies to highlight aspects such as the Ha rich star forming regions.

For nova I suspect that the realistic option is going to be one of each ultimately, a UHC that allows Ha+OIII through, a dedicated OIII and a dedicated Ha. There will be times when one does better then the others. Mind you I tend to collect "sets" of things, like TV plossl's, BST Starguiders, WO SWANS etc. I always end up with the complete bunch.

[JTmunmun]

3 hours ago, John said:

They say that the best investment to get great galaxy views is some fuel in your tank to take you and the scope to a dark sky site

That said, my backyard has some light pollution issues but I've still managed to see many galaxies down to around magnitude 13.8 with my 12" scope. I've not found a filter of any sort that improved the views of galaxies though, despite trying broadband / light pollution types. I found that I sold these on rather quickly wheras the UHC and O-III type have proved very valuable for nebulae.

I have heard that too  - unfortunately a true dark sky site is about 2.5 hours away. So I am torn about purchasing the UHC or OIII first. According to the Lumicon guide to filters, OIII supposedly performs better in light pollution. Can anyone confirm the OIII is better in light pollution vs. the UHC? Or is it mostly going to depend on the object being viewed?

[N3ptune]

@JTmunmun The NPB filters, they have a good reputation and a nice price for a combo, 2" and 1 1/4", similar to UHC. They help a lot on many nebulae, I use them all the time and I honestly love these filters.

http://www.npbfilters.com/

 

[N3ptune]

@JTmunmun Everything is subtle in astronomy, but I am telling you, the 2" NPB used with a 32mm 2" eyepiece on the Orion's great nebula, it's amazing    The nebula is far more visible, it has far more contrast.  I can see some parts of the Veil nebula, the Monkey head, the the North America Nebula and even parts of the Pelican Nebula with the same 2" filter / 32mm EP, all of these are otherwise invisible with my 203mm reflector in a medium sky.

[JTmunmun]

Since I do plan on astroimaging eventually, do the UHC and OIII fare well for imaging in light pollution, or is it better to get a separate broadband like Astronomik CLS for that? or is the answer mostly "depends on what you're imaging?"

[JTmunmun]

3 minutes ago, N3ptune said:

@JTmunmun Everything is subtle in astronomy, but I am telling you, the 2" NPB used with a 32mm 2" eyepiece on the Orion's great nebula, it's amazing    The nebula is far more visible, it has far more contrast.  I can see some parts of the Veil nebula, the Monkey head, the the North America Nebula and even parts of the Pelican Nebula with the same 2" filter / 32mm EP, all of these are otherwise invisible with my 203mm reflector in a medium sky.

That was kind of another thing I was wondering. Is it worth getting the 2" filters? I have an 8" reflector, an F/5, and only have one 2" eyepiece at 35mm so it didn't seem worth it to get it over the 1.25". Perhaps with the combo price for the NPB though it is worth it, being cheaper than the Lumicon 2" for both.

[N3ptune]

People here have suggested me to get a 2" filter with a 2" eyepiece with large exit pupil to look especially at large and faint nebulae. I also use the 1 1/4" filter on smaller planetary nebulae with a 1 1/4 EPs and barlow, often. I wanted to have both size to be able to use low power and high power with a UHC filter. That's why I liked the combo deal

--> The most important thing, I see much more nebulae with the filters.

[JTmunmun]

7 minutes ago, N3ptune said:

People here have suggested me to get a 2" filter with a 2" eyepiece with large exit pupil to look especially at large and faint nebulae. I also use the 1 1/4" filter on smaller planetary nebulae with a 1 1/4 EPs and barlow, often. I wanted to have both size to be able to use low power and high power with a UHC filter. That's why I liked the combo deal

--> The most important thing, I see much more nebulae with the filters.

Do you have any issue with red tinted stars with that? I read on some forum post that someone had that issue with the NPB, but there were also some in the same thread that said they didn't have that at all. 

[N3ptune]

That's true, some stars will appear to have red/green tint in some angle, I noticed that the first time I used the filters, but that's about it, it's no big deal for me considering the enhancement on nebulosity and it's not super strong red either.

With my OIII filter, the stars are green.

[JTmunmun]

2 hours ago, N3ptune said:

That's true, some stars will appear to have red/green tint in some angle, I noticed that the first time I used the filters, but that's about it, it's no big deal for me considering the enhancement on nebulosity and it's not super strong red either.

With my OIII filter, the stars are green.

Interesting! Is that specific to the NPBs or do pretty much all of the UHCs and OIIIs do that?

[Stu]

3 hours ago, JTmunmun said:

Interesting! Is that specific to the NPBs or do pretty much all of the UHCs and OIIIs do that?

My Lumicon UHC and OIII turn the stars green but have a fantastic effect on nebulosity. The DGM NPB leaves the stars more neutral but they do show a red/green split to them if you look at them directly. If you are concentrating on the nebulosity it is not so much of a problem.

[YKSE]

12 hours ago, ronin said:

Yes they only really help, or help most significantly, on nebula as these tend to fall into being "strong" in either Ha or OIII, will depend on what was created when the star went nova and the nature therefore of the emissions. So you filter to allow this strong one through and block the remainder, and hence increase the contrast. All gets complicated as you really first need to find the spectral emissions you will get. Which is often done by syicking a filter in and seeing what effect it has.

Strange maybe but we seem toi have little talk of images and spectra at the S lines.

Galaxies being "white" are not strong at one specific wavelength. So a dark sky is the best. People use an Ha filter on galaxies to highlight aspects such as the Ha rich star forming regions.

For nova I suspect that the realistic option is going to be one of each ultimately, a UHC that allows Ha+OIII through, a dedicated OIII and a dedicated Ha. There will be times when one does better then the others. Mind you I tend to collect "sets" of things, like TV plossl's, BST Starguiders, WO SWANS etc. I always end up with the complete bunch.

Ronin,

 As you've mentioned many times that you don't have a filter, so a natural quesions is: Have you ever observed with a filter? What can you see through a H-alfa filter? Do you know anyone who has used a H-alfa filter to see a nebula (not using NV-device i.e.)?