32 replies to this topic

[Starman1]

Here is the latest 2024 visual-use nebula filters buyer's guide.

This year, I have eliminated photographic filters so the spreadsheet is oriented only to visual filters.

 

Photographic filters are far more numerous in number and type and there are more manufacturers for them.

 

Some notes: It appears Optolong may be abandoning visual use filters in favor of photographic filters.  They are not generally available.

There may be more money and profit in imaging filters.

 

Many of the eBay/Amazon/Ali Express nebula filters have been disappearing, signaling that is may be getting harder to find low cost manufacturers willing to do small runs of filters.

 

Lumicon is now available again, direct from the manufacturer rather than dealers.

 

Many visual filters seem to be only spotty in availability, so if the filter you favor is available now, buy it now.  It might not be available later.

Attached Files

•  2024 Visual Use Nebula Filter Buyer's Guide.xlsx   14.07KB   1556 downloads

[eyeoftexas]

Thanks, Don, as always for compiling this and the the eyepiece list.  

[Starman1]

bump

[star69]

I motion to have this post pinned. 
 

Thanks again Don. Especially for excluding the imaging filters. They can sure muddy up the works when looking for visual filters. 

[Starman1]

I motion to have this post pinned.

Thanks again Don. Especially for excluding the imaging filters. They can sure muddy up the works when looking for visual filters.

It's not that some imaging filters can't be used for visual use, but that, in general, they will be too dark or highlight the wrong spectral lines for the sensitivity of the eye.
When I was visually testing several dozen different filters, I used some photographic one-line O-III filters, and they did highlight small bright areas in some nebulae, but at the expense of the overall size of the nebulae, especially the outer faint parts. And the serious reduction in brightness of the field made acquiring and holding the exit pupil more difficult.

If you could afford to have a few dozen filters and had a way to switch them, it would be a way to investigate some small details in a particular nebula.

Most people will have one narrowband filter and one O-III filter, however, so having filters that are easy to use and show you as much as possible is more desirable, and that is why I excluded photographic filters. They're just not the optimum filters for visual use.

[miguel gonzalez]

Now that lumicon is once again producing UHC filters made in the USA, I wonder how it compares to the other premium filters.

[sanbai]

My strong guess is that Lumicon now refers to the products sold by LumiconInc and not those from Farpoint. [I won't comment on that soap opera]
Farpoint, although still showing "Lumicon" name in their website, do not list any actual product in there.

 

I'm would be curious to know how it compares the OIII-Gen3 that Farpoint was selling to the one sold by LumiconInc. I'm not sure it's the same. I got mine in 2019 directly from Farpoint.

Same for the UHC-"gen3" - I got what I think was the "Farpoint" one in 2020 from a great and respected dealer that went into retirement.

 

What seems to be gone is the "comet" filter. I got one of those in one of those 50% sales that Farpoint made when I could still trust that shop.

[Herodotus]

Thanks Don for putting this together.

[Starman1]

My strong guess is that Lumicon now refers to the products sold by LumiconInc and not those from Farpoint. [I won't comment on that soap opera]
Farpoint, although still showing "Lumicon" name in their website, do not list any actual product in there.

 

I'm would be curious to know how it compares the OIII-Gen3 that Farpoint was selling to the one sold by LumiconInc. I'm not sure it's the same. I got mine in 2019 directly from Farpoint.

Same for the UHC-"gen3" - I got what I think was the "Farpoint" one in 2020 from a great and respected dealer that went into retirement.

 

What seems to be gone is the "comet" filter. I got one of those in one of those 50% sales that Farpoint made when I could still trust that shop.

Check out the 25-28nm bandwidth "Wide O-IIIs"

Some of them cover the 511nm and 514nm C2 lines as well as the 500.7nm O-III line, so could be considered "Comet" filters.

Check the graphs for them to make sure they cover those lines.

See:

Click the C2 lines on the upper right and deselect the Chroma filters.

Then, start checking out the O-III filters (Star Guy = older Optolong)

https://searchlight....9d-153d7e7c0eb8

Omegon?  Castell?  Both graphs look possible for the C2 lines.

[PalomarJack]

Sorry, a little late to this party. But there is a particular vendor completely missed, but not in the Buyers Guide, and they show no indication of cutting back on visual filters, they even have added some to their lineup. SVBONY, yes, yes, I know, they're made it China and are not quite as good as the likes of Lumicon and Optolong, but at 1/4 the price and 90% to 95% of the performance, who cares? They are perfect for those just starting out. Besides, they can use them later at outreach events and save the good stuff for dark sky locations. Or, sell them to the next novice observer.

 

How good? Let's say that the OIII in my 8" f/6 under fair conditions the Vail Nebula goes from just noticeable to very obvious WITH detail. The Rosette goes from invisible to obvious. And the UHC is just a good.

Edited by PalomarJack, 04 December 2024 - 12:12 AM.

[Starman1]

Huh?

There are 4 Svbony filters in the guide:

Bandwidths are next to the models:

CLS 64nm  --should be OK as a broadband.
UHC 50nm  --way too wide to be an effective narrowband filter.  There are better inexpensive narrowband filters.
H-Beta 25nm --ridiculously wide bandwidth.  You should avoid.
O-III 18nm --A bit wide, but t gets a pass, given its price.

 

Optolong filters are made by Yulong in China, but their emphasis these days seems to be imaging filters rather than visual.

There are still 5 visual-use Optolong filters in the Buyer's Guide, though.  I wouldn't rate them as high-end filters in the realm or Astronomik, Tele Vue, Lumicon or DGM, however.

[Olimad]

After close to 2 years observing, I have seen that I mainly use OIII and H-Beta filters. I have bought both from SVBony at really low prices.

 

I know now a bit better what I am using, I know now how to clean them and keep them without messing things Up. So I decided that I will try a premium filter, to see if things are better for me that way.

 

I have seen the Baader OIII super gen3 filter. It is around 90 euros, and is 9mm. 

Would It be a good filter, or is there another one at these prices that is worth to have?

Thanks in advance.

[Starman1]

After close to 2 years observing, I have seen that I mainly use OIII and H-Beta filters. I have bought both from SVBony at really low prices.

I know now a bit better what I am using, I know now how to clean them and keep them without messing things Up. So I decided that I will try a premium filter, to see if things are better for me that way.

I have seen the Baader OIII super gen3 filter. It is around 90 euros, and is 9mm.
Would It be a good filter, or is there another one at these prices that is worth to have?
Thanks in advance.

It is a single line photographic O-III filter.
Photographic filters cut 25% of the O-III energy but exposures can be lengthened to compensate.
For visual use, you want both O-III lines to pass through at 90% or more, and that rules out Baader, Thousand Oaks and many others.
You will see less nebula than a dual line filter.

If you want a good visual use O-III filter, look to:
Astronomik O-III visual
Tele Vue Bandmate II O-III
Lumicon O-III
All have approximately a 12nm bandwidth.
There is not a good O-III 2" visual filter for that low a price.

[Eric Weder]

Thank you for your efforts, Don!

 

Merry Christmas!

[Arnau_BCN]

Baader also have OIII filters for 1.25 and 2” size. They actually have 2 models in 10nm and 15nm. I personally tried the OIII in 10nm and it worked well.

[Starman1]

Baader also have OIII filters for 1.25 and 2” size. They actually have 2 models in 10nm and 15nm. I personally tried the OIII in 10nm and it worked well.

The Baaders were not included in the list because they are single line photographic filters. Visual filters should pass both O-III lines.
My Baader O-III also had a fairly low transmission at the 500.7nm line.
The Astronomik 12nm got both lines and displayed larger amounts of nebulosity.

Edited by Starman1, 08 January 2025 - 02:39 AM.

[AstroDani89]

Here is the latest 2024 visual-use nebula filters buyer's guide.

This year, I have eliminated photographic filters so the spreadsheet is oriented only to visual filters.

 

Photographic filters are far more numerous in number and type and there are more manufacturers for them.

 

Some notes: It appears Optolong may be abandoning visual use filters in favor of photographic filters.  They are not generally available.

There may be more money and profit in imaging filters.

 

Many of the eBay/Amazon/Ali Express nebula filters have been disappearing, signaling that is may be getting harder to find low cost manufacturers willing to do small runs of filters.

 

Lumicon is now available again, direct from the manufacturer rather than dealers.

 

Many visual filters seem to be only spotty in availability, so if the filter you favor is available now, buy it now.  It might not be available later.

Thank you for this very informative list! I purchased a few filters with the hopes of seeing nebulas visually, and found out I have either the wrong filter or the wrong skies    ....I mean bortle scale for the filters I have. I've been trying to look each one of them up to learn more about them so that I can try to make use of what I now have. I have the ES hydrogen-beta filter and was wondering if you could tell me what the N9859 on it means. Nothing is popping up online for that information specifically. Like with the Hydrogen-alpha filter, I've learned there's different bandwidths and nm I should be checking for prior to purchasing. From your list, I learned the h-beta filter that I have is an 18nm as opposed your recommended 8 or 9 nm. How would I, as the complete novice, know where to look to get this information during any given purchase. Not every retailer actually lists this. For example, I only know the bandwidth of my ES H-beta filter because you provided it. I didn't find your list until well after my purchase. Thanks in advance!

[Starman1]

Well,

1) the most useful nebula filter is a narrowband.

It should pass the 486.1nm H-ß line and the 495.9 and 500.7nm O-III lines at >90%.

It should have a bandwidth (Full-width, half maximum, or FWHM) of 22-27nm for best results.

Without knowing the spectrum of the nebula, it will work for:

--planetary nebulae

--large emission nebulae with star forming regions, like M42/43, M8, M17, M20, M16, NGC7000, etc.

--Wolf Rayet excitation nebulae, like NGC6888, or NGC2359

--large emission nebulae without star formation, like IC434, et.al.

--supernova remnants like M1, or the Veil nebula

2) the next most useful filter is an O-III filter.

It should pass BOTH the 495.9nm and 500.7nm O-III lines at >90%

It should have a FWHM bandwidth of 11-13nm for best results.

It will work best for planetary nebulae, supernova remnants and Wolf-Rayet excitation nebulae.

3) the least useful nebula filter is an H-ß filter.

It should pass the 486.1nm H-ß line at >90% and have a bandwidth (for visual use) of 6.5-9nm.

It will work best on the large hydrogen emission gas clouds that are low surface brightness, many without star formation.

It is not the best filter for most nebula, and its more limited use is why I rank it 3rd.

 

Nebulae not helped by a filter:

--reflection nebulae (exception: when associated with a large emission nebula)

--dark nebulae.  This requires excellent contrast found in dark skies.

 

And, of course, no other object is really helped much by a filter.

The one exception is a very wide O-III filter that has a bandwidth that extends upward to cover the 511nm and 514nm C2 lines found in comet tails.

An example of one of these: Omegon O-III filter, with a 25nm bandwidth that extends up to 517.5nm.

I wouldn't recommend it as your only O-III filter, though.

Edited by Starman1, 16 January 2025 - 06:58 PM.

[Starman1]

Hi.

I have an older Thousand Oaks OIII 1.25" filter that i only use for visual in a 12" scope, would it make sense to replace  it with a Astronomik OIII?  

 

Mikkel

Most tests of the TO O-III filters show they only pass the 500.7nm O-III line, like the Baader and Celestron O-III filters.

That makes them OK for imaging, but not visual, IMO.

The Astronomik O-III passes for O-III lines, letting a lot more O-III energy through.

You would find the nebulae more extensive and a bit brighter (33% brighter, since the output at 495.9nm is about 1/3 as much as at 500.7nm).

 

I might comment that a 2" filter is more universal, as it fits 2" eyepieces (important for low powers used on nebulae) and fits most 1.25" to 2" adapters for use with 1.25" eyepieces,

as well as fitting 2" Barlows and coma correctors.

Edited by Starman1, 20 January 2025 - 10:55 AM.

[Brain&Force]

Here is the latest 2024 visual-use nebula filters buyer's guide.

This year, I have eliminated photographic filters so the spreadsheet is oriented only to visual filters.

 

It's not that some imaging filters can't be used for visual use, but that, in general, they will be too dark or highlight the wrong spectral lines for the sensitivity of the eye.
When I was visually testing several dozen different filters, I used some photographic one-line O-III filters, and they did highlight small bright areas in some nebulae, but at the expense of the overall size of the nebulae, especially the outer faint parts. And the serious reduction in brightness of the field made acquiring and holding the exit pupil more difficult.

Would you be open to including photographic filters in this list if they have been reported to be usable visually? I've personally found the Svbony SV240 multi-narrowband to be a very good UHC with a measured FWHM of about 25 nm (better than the 50 nm FHWM of Svbony's UHC), and there are reports from German observers about successfully using the Baader 5.5 nm CMOS optimized H-beta filter visually.

 

I'm personally interested in testing more photographic filters to see if any are hidden gems for visual observers.

[Starman1]

To be honest, I don't think I will do another Filters Guide.

The number of visual use filters is declining, and most of them are very cheap and poor quality from eBay or AliExpress.

It would be a very short list if confined only to the high-quality ones.

Several of the companies on the list have stopped selling visual-use filters, too.

 

Svbony's transmission graph for the SV240 filter seems to show a sharp dip in transmission at the 500.7nm O-III line, which is a bit weird, and maybe another dip at the 495.9nm O-III line as well.

Also weird is the IR band transmission, which wouldn't help the astrophotographer much.

DSLRs would filter it out, and astrocameras would see it as noise.

Perhaps that wouldn't matter much visually, and it is inexpensive.

[Brain&Force]

Svbony's transmission graph for the SV240 filter seems to show a sharp dip in transmission at the 500.7nm O-III line, which is a bit weird, and maybe another dip at the 495.9nm O-III line as well.

Also weird is the IR band transmission, which wouldn't help the astrophotographer much.

DSLRs would filter it out, and astrocameras would see it as noise.

Perhaps that wouldn't matter much visually, and it is inexpensive.

The choice to include an IR passthrough for a photographic filter baffles me, honestly. Unless you have an all-reflecting setup (or at least an OTA that's very well corrected in the near IR) it's just asking for trouble. I'm surprised this isn't just sold as a UHC, but with companies moving towards selling photographic filters I guess it's a marketing move. Svbony's own site says the SV240 is not suitable for visual use - I guess nobody there bothered to test it visually.

 

It's interesting to see that the bumpiness in the 480-500 nm region is corroborated in the independent transmission measurement. I tend not to trust the measurements provided by retailers (I have seen clearly incorrect or even reused data in filter marketing material) but they seem to correspond within the realm of expected sample variation.

[j.gardavsky]

...

 

I'm personally interested in testing more photographic filters to see if any are hidden gems for visual observers.

Here are reports on the visual use of the photographic OIII filters on some planetary nebulae:

 

Abell 74, Astrodon OIII 5nm:
https://www.cloudyni...lecular-clouds/

 

FP J1912-0331, Astrodon OIII 5nm:
https://www.cloudyni...bula-candidate/

 

PaRasMoMi 1, Astrodon OIII 5nm and 3nm:
https://www.cloudyni...nd-snr-g206923/

 

These photographic filters have been visually also helpful on more than a dozen of the supernova remnants, discovered since the NGC and IC catalogs have been completed.

 

Back to the Baader H-beta 5.5nm (CMOS)

This filter has turned out to be a game changer during the visual observations of numerous HII regions.

 

Not counting the planetary nebulae, I have observing notes about the filter use on 470 galactic nebulae (star birth regions, SNR and their candidates, Wolf-Rayet nebulae, shells and supershells, HII regions, and other nebulae from the recent sky surveys).

 

Clear skies,

JG

 

 

[George9]

Thanks so much for the list, Don.

 

I would put the Baader 5.5nm H-beta filter in the visual list. Know it has "CMOS optimized" in the name, but if you look at the Baader product information, it is clearly marketed as a visual filter with a long explanation of why by Baader.

 

Unlike the photographic OIII filters that cut out some of the signal to achieve better signal-to-noise, the Baader 5.5nm H-beta filter does not sacrifice any true signal. And unlike an H-alpha filter, the eye is sensitive enough at H-beta.

 

Yes, the stars get dark, but the nebulae come through so much better. In my old Astronomik 14nm H-beta, it helped on the classic objects like the California and the Horsehead, but it was always a struggle. With the Baader 5.5nm the object is right there in the eyepiece. I mainly use an 18" f/4.3 Starmaster. The filter is expensive, admittedly. I think it is more than twice as good as my old H-beta filter, and it cost twice as much.

 

I see you have the Chroma 5nm H-beta filter in the list, so why not also the Baader 5.5nm?

 

George

 

(My main filters are now Lumicon gen3 OIII, TV Bandmate 2 OIII, DGM NPB, Baader 5.5nm H-beta, Orion Ultrablock. I was going to sell the TV OIII when I got the Lumicon gen3, but I ended up using them both objective-mounted on my 10x42 binoculars. I can also put the NPB and Ultrablock on the binoculars.)

[PalomarJack]

...And, of course, no other object is really helped much by a filter...

Actually Narrow band filters work well for hydrogen regions of some face on external galaxies, like M33. One night another club member and I tried a narrow band and H-Beta filters on M33 through a 24" f/4. He was quite surprised at how well it worked. Of course more distant galaxies, ellipticals and edge-on spirals are not even worth the effort.