Triad Narrowbandfilters

[Matzi]

Hi

 

I'm seriously considering buying one of those new triad/tri narrowband filters for DSLR/OSC cameraes out there.

So far I'm only aware of two existing, the relatively cheap Optolong L-eNhance, and the expensive OPT Multiband Triad.

Are there any others on the marked than those two? And is there a huge difference in the quality of images when using either one, since the OPT Triad costs 4x times as much as the L-eNhance?

-Mats

[Star101]

I know nothing about these filters. I have heard some people talking of buying and reviewing but so far I have seen no reviews.

A quick search on AB shows some image results.

Triad filter

L-eNhance filter

 

 

[david_taurus83]

@StaceStar has recently acquired an Altair Astro triband filter but I cant for the life of me find a link?!?!

[jjosefsen]

Astrobackyard.com has a review of the Optolong L-eNhance filter.

 

 

Trevor is perhaps not the most critical reviewer of products out there, but maybe the video can answer some of your questions.

 

Many of the images I see with these kinds of filters are predominantly red, and usually not much else, which is a shame really.

But it might be down to how you process the data from these filters, here is an example from Tommy Lim who does product testing for Optolong (I think..!):

https://pbs.twimg.com/media/D6K54aHUYAEQJwV.jpg:large

It shows more color variation than I usually see from these kind of filters.

 

All in all I find it very interresting, especially as time is such a limit for me.. Capturing everything in one go is very tempting.

Edited June 19, 2019 by jjosefsen

[Matzi]

16 minutes ago, david_taurus83 said:

@StaceStar has recently acquired an Altair Astro triband filter but I cant for the life of me find a link?!?!

I did hear about Altair Astro producing some too, but I've searched for them without any luck?

 

I'm having a bit of a hard time seeing a big difference between the quality in the images, but considering the Optolong L-enhance is 4x as cheap as the OPT, you probably get most value for the money there?

The Optolong L-enhance is what 12-13nm of Ha, Hb and OIII, while the OPT Triad is 4 nm Ha, OIII, 5nm Hb? So it should have some difference in detail there?

As for the red color dominating the images, well it's quite simple, most nebulae consist mostly of Hydrogen Alpha, and it's of the red color, but HOO and even processing in SHO is possible, I've seen a couple of SHO images from these filters as well.

 

But I agree Trevor Jones is not the most "trusted" critiq out there.

[jjosefsen]

1 hour ago, Matzi said:

I did hear about Altair Astro producing some too, but I've searched for them without any luck?

 

I'm having a bit of a hard time seeing a big difference between the quality in the images, but considering the Optolong L-enhance is 4x as cheap as the OPT, you probably get most value for the money there?

The Optolong L-enhance is what 12-13nm of Ha, Hb and OIII, while the OPT Triad is 4 nm Ha, OIII, 5nm Hb? So it should have some difference in detail there?

As for the red color dominating the images, well it's quite simple, most nebulae consist mostly of Hydrogen Alpha, and it's of the red color, but HOO and even processing in SHO is possible, I've seen a couple of SHO images from these filters as well.

 

But I agree Trevor Jones is not the most "trusted" critiq out there.

Yeah I realise Ha is the most dominant type of gas in most nebulae.

But I was looking at an HOO image of M17 (mono sensor) the other day, and compare that to Trevor's M17, shot with OSC through the multi band pass filter.

There was much more blue in the mono image. But like you I have seen some pretty good SHO / HOO simulations made with OSC and these filters.

[thomasv]

I've just ordered what I think is the IDAS version of these:

https://www.firstlightoptics.com/light-pollution-reduction-imaging/idas-narrow-band-nebula-nb1-filter.html

Not in stock, so it'll be a while before I get it.

 

 

[Matzi]

43 minutes ago, thomasv said:

I've just ordered what I think is the IDAS version of these:

https://www.firstlightoptics.com/light-pollution-reduction-imaging/idas-narrow-band-nebula-nb1-filter.html

Not in stock, so it'll be a while before I get it.

 

 

It could sound as it is a competitor to the Optolong L-eNhance and the OPT Triad, but I can't read at which nm each individual NB is at?

I couldn't find it either on the Optolong, but a friend of mine told me it is at 12-13nm of Ha, hb and OIII, whilst the OPT is down at 4nm Ha, and OIII, 5nm Hb, but it is also a whole lot more pricier!

[vlaiv]

I think that these are very interesting filters, but I also think that most people don't use them "properly". Best way to utilize them in my view is in conjunction with regular narrow band filters to form sort of "LRGB" set for narrow band imaging (meaning mono camera).

Such tri-band or quad-band filter would act as luminance - having higher total SNR as it would combine signal from all sources of interest in single frame (reducing impact of read noise which is significant in NB imaging). Single narrow band filters can then be used for much shorter as they provide only "color" information or rather separation of signal types. Here one can exploit the fact that targets have dominant emission(s) - usually it is Ha and one other (either SII or OIII) - this means that you can end up with shooting only those stronger lines and calculate remaining one (each strong component will have better SNR and there is a subtracting stacks is in fact additional stacking - odds are that third component will end up being better SNR then if shot directly with that filter).

[Starflyer]

Some info here;

https://m.facebook.com/groups/872838536154502?view=permalink&id=1966374236800921

 

 

[Adam J]

Personally I would want to see the narrowest oiii filter and ha filter possible and I think all this talk of Tri / quad filters that include Hb and SII is marketing spin designed to mitigate the fact that not all the manufacturers are able to create duel band pass narrowband filters with sufficiently narrow band pass to isolate oiii from Hb and or Ha from SII and so want to present this as a design feature when really on an OSC Hb and SII are not going to bring much to the party. So my recommendation would to get the a duel band pass filter with the narrowest oiii bandwidth available and forget about Tri and quad.

Adam 

 

[Matzi]

9 hours ago, vlaiv said:

I think that these are very interesting filters, but I also think that most people don't use them "properly". Best way to utilize them in my view is in conjunction with regular narrow band filters to form sort of "LRGB" set for narrow band imaging (meaning mono camera).

Such tri-band or quad-band filter would act as luminance - having higher total SNR as it would combine signal from all sources of interest in single frame (reducing impact of read noise which is significant in NB imaging). Single narrow band filters can then be used for much shorter as they provide only "color" information or rather separation of signal types. Here one can exploit the fact that targets have dominant emission(s) - usually it is Ha and one other (either SII or OIII) - this means that you can end up with shooting only those stronger lines and calculate remaining one (each strong component will have better SNR and there is a subtracting stacks is in fact additional stacking - odds are that third component will end up being better SNR then if shot directly with that filter).

I agree, it definately would act as a great super/master luminance for mono cams!

But it does indeed show narrowband quality, even with OSC/DSLR, you can tell a huge difference between normal RGB, and the use of either tri/quad filter. Also it helps a lot of people dealing with a high light pollution, but in my case my backyard is Bortle Class 4, so I'd imagine it would look even better.

I own a Baader 2" 7nm HA, and a Baader 2" 8.5nm OIII filter, but getting those narrowband details in one image, AND not having to deal with 3 different stacks, but your image comes out as instant HOO is kinda nice.

 

7 hours ago, Adam J said:

Personally I would want to see the narrowest oiii filter and ha filter possible and I think all this talk of Tri / quad filters that include Hb and SII is marketing spin designed to mitigate the fact that not all the manufacturers are able to create duel band pass narrowband filters with sufficiently narrow band pass to isolate oiii from Hb and or Ha from SII and so want to present this as a design feature when really on an OSC Hb and SII are not going to bring much to the party. So my recommendation would to get the a duel band pass filter with the narrowest oiii bandwidth available and forget about Tri and quad.

Adam 

 

The narrowest Triad filter out there is 4nm HA, OII, and 5nm HB. But I know you can actually isolate the HA, SII, and OIII, not sure about the Hb in APP, and I can't really see what the Hb is doing for the images, at least not colorwise, but I do see more structual details in nebulae with these filters, compared to Duo/or single NB filters, I'm not sure why, if it's the Hb that helps with that, of if it is just me.

[Adam J]

12 hours ago, Matzi said:

I agree, it definately would act as a great super/master luminance for mono cams!

But it does indeed show narrowband quality, even with OSC/DSLR, you can tell a huge difference between normal RGB, and the use of either tri/quad filter. Also it helps a lot of people dealing with a high light pollution, but in my case my backyard is Bortle Class 4, so I'd imagine it would look even better.

I own a Baader 2" 7nm HA, and a Baader 2" 8.5nm OIII filter, but getting those narrowband details in one image, AND not having to deal with 3 different stacks, but your image comes out as instant HOO is kinda nice.

 

The narrowest Triad filter out there is 4nm HA, OII, and 5nm HB. But I know you can actually isolate the HA, SII, and OIII, not sure about the Hb in APP, and I can't really see what the Hb is doing for the images, at least not colorwise, but I do see more structual details in nebulae with these filters, compared to Duo/or single NB filters, I'm not sure why, if it's the Hb that helps with that, of if it is just me.

Well Ha and SII are both covered by the red pixels and so you will never separate them using an OSC camera as both will appear red. As for the Hb being in the same places as the Ha all its going to do is shift the Ha red towards pink, something that can be done in processing anyway. 

Adam 

[Matzi]

10 hours ago, Adam J said:

Well Ha and SII are both covered by the red pixels and so you will never separate them using an OSC camera as both will appear red. As for the Hb being in the same places as the Ha all its going to do is shift the Ha red towards pink, something that can be done in processing anyway. 

Adam 

APP can actually seperate them, but then again what for? Surely you can process each narrowband wavelength as if they were done from a mono with individual filters, but then why not just use a mono cam? Except you can capture this data using just one filter though. And you can always simulate a SHO with this. And yes I know SNR is a lot better on a mono, so there's that.

But I don't really like the broad OIII/Hb on the dual and triads. OPT's Quad filter is the only with true narrow wavelengths at 4nm on Ha, SII and OIII.

I think it's still a great invention for those people who are fighting light polluted skies, have a fighting chance for some decent AP, and with narrowband quality in their images. When I bought my 7nm Ha, and 8.5nm OIII it was before these duo/triad filters came out, and right now I kinda wish I had bought one of these instead, to simpify things.

[StaceStar]

On 19/06/2019 at 10:10, david_taurus83 said:

@StaceStar has recently acquired an Altair Astro triband filter but I cant for the life of me find a link?!?!

Mine is a pre production one, they made about 10 of the quad and 10 of the tri...so sold out very quickly. However if you keep an eye on the site they will be making more soon

 

Also incidentally got first light last night, this is only 14x 240s. (with 3 darks and 0 flats)...will be adding more data tonight. Yes i'm a glutton for punishment imaging on the shortest nights of the year hahah. Either way i am massively impressed. 

 

 

[StaceStar]

Also, please note that was a 5 minute 2am process haha, I used APP to stack ...but used the Ha-Oiii colour algorithm rather than AAD 

[Matzi]

Hi StaceStar!

I did see your image here on the AA FB page just an hour ago, and I must admit it is the most promising image I've seen there yet! There were also one done with the quad filter, on the Cresent nebula, but that really didn't impress me. I don't know if it was due to some sort of problems, or bad processing. But I'd really like to know the nanometer values on each narrowband wavelengths (I know this probably don't matter much, it's the images the filters help produce in the end) But I always like to compare stuff on papers, and then the images they produce afterwards.

 

I'm really looking forward to see your final results on your image with the triad filter!

[astrosathya]

2 hours ago, StaceStar said:

Mine is a pre production one, they made about 10 of the quad and 10 of the tri...so sold out very quickly. However if you keep an eye on the site they will be making more soon

 

Also incidentally got first light last night, this is only 14x 240s. (with 3 darks and 0 flats)...will be adding more data tonight. Yes i'm a glutton for punishment imaging on the shortest nights of the year hahah. Either way i am massively impressed. 

 

 

Hi Stacey, please could you post an unprocessed(unstretched too) single frame? Just to look at what the data looks like right out of the camera.

[Adam J]

16 hours ago, Matzi said:

APP can actually seperate them, but then again what for? Surely you can process each narrowband wavelength as if they were done from a mono with individual filters, but then why not just use a mono cam?

APP cant separate Ha from SII, thats not possible and to be honest due to the overlap between Green and Blue pixels at the OIII wavelength you cant correctly separate Hb from OIII either. The only channels that APP can fully separate out are Ha and OIII....well unless someone makes a Hb / SII duel band filter at any rate.

The main advantage of a duel narrow band filter (Ha and OIII only) is that it allows you to image the two wavelength at the same time with an OSC and hence increases the efficiency of OSC narrow band imaging which is normally well behind that of a mono camera.  Problem is that the OIII wavelength tends to be much wider band pass than on a dedicated OIII filter and so it still suffers more from LP than individual filters and as the peak of the green filter pass does not match the OIII centre wavelength you also lose efficiency due to lower QE too. But its better for OSC in terms of overall efficiency. 

But like I say there really is not point in trying to include SII and Hb into the mix as all you are doing is harming signal to noise while also not being able to process them as separate channels. 

Adam

 

Edited June 21, 2019 by Adam J

[StaceStar]

1 hour ago, astrosathya said:

Hi Stacey, please could you post an unprocessed(unstretched too) single frame? Just to look at what the data looks like right out of the camera.

hi! here are those files you asked for, all single 240s frames just converted to JPEG. 

First is a single frame unstretched, second is a single frame with a medium stretch but background not neutralized, third is a single frame with the same stretch but the back ground neutralised. 

None are dark corrected so thats why there is the typical 183 sensor glow on the right side.

[Matzi]

29 minutes ago, Adam J said:

APP cant separate Ha from SII, thats not possible and to be honest due to the overlap between Green and Blue pixels at the OIII wavelength you cant correctly separate Hb from OIII either. The only channels that APP can fully separate out are Ha and OIII....well unless someone makes a Hb / SII duel band filter at any rate.

 

Hi Adam, yes my bad, APP can only seperate HA and OIII

[StaceStar]

1 hour ago, Matzi said:

Hi StaceStar!

I did see your image here on the AA FB page just an hour ago, and I must admit it is the most promising image I've seen there yet! There were also one done with the quad filter, on the Cresent nebula, but that really didn't impress me. I don't know if it was due to some sort of problems, or bad processing. But I'd really like to know the nanometer values on each narrowband wavelengths (I know this probably don't matter much, it's the images the filters help produce in the end) But I always like to compare stuff on papers, and then the images they produce afterwards.

 

I'm really looking forward to see your final results on your image with the triad filter!

Hiya! Thank you for the kind words about my image, its still a work in progress but im very hopeful. A bit about where i image from, I live in Birmingham and my skies vary from bortle 6-8 depending on direction, I also have LED streetlights, the moon was up a bit last night and very bright....plus finally it didnt really get that dark at all last night. So in short i think this filter is brilliant.  I too saw the crescent image and i'm not entirely sure what has gone on there, but for me this filter has made quite the impact

[Matzi]

1 minute ago, StaceStar said:

Hiya! Thank you for the kind words about my image, its still a work in progress but im very hopeful. A bit about where i image from, I live in Birmingham and my skies vary from bortle 6-8 depending on direction, I also have LED streetlights, the moon was up a bit last night and very bright....plus finally it didnt really get that dark at all last night. So in short i think this filter is brilliant.  I too saw the crescent image and i'm not entirely sure what has gone on there, but for me this filter has made quite the impact

Well I live in Denmark, so I bet we have pretty similar annoying bright nights at summertime right now. Is the veil nebula at it's peak at this northern location right now, or can it still be imaged when fall arives, and darker nights?

My backyard is a Bortle Class 4, 20.97 SQM, so hopefully that'll help as well. Do you know if the Tri and Quad filter is at the same price right now? I do hope for some better images done with the Quad arrives, because so far the tri-filter looks best. But looking forward to see your finished image with this one

 

@Adam J I get your point, so a duo-narrowband filter would work best for an OSC/DSLR? But what about the Hb in the Triad, or SII in the Quad, won't they make some sort of improvement in the structual details in a nebula, compared to a duo?

[astrosathya]

On 21/06/2019 at 18:44, StaceStar said:

hi! here are those files you asked for, all single 240s frames just converted to JPEG. 

First is a single frame unstretched, second is a single frame with a medium stretch but background not neutralized, third is a single frame with the same stretch but the back ground neutralised. 

None are dark corrected so thats why there is the typical 183 sensor glow on the right side.

Thank You so much Stacey. This is exactly what I hoped to see. Greatly appreciate your reply. 

[Matzi]

I'm starting to wonder if I use my Baader 7nm Ha, and 8.5 nm OIII, if that will yield better results, than a duo/tri filter...