OSC NB filter

[Anthonyexmouth]

What's the best bang for buck dual NB filter at the moment? preferably one with minimal halo issues. 

[Budgie1]

I never thought I'd say this, as someone who started off using DSLR then OSC but;

If you want the best value for money and halo free narrowband imaging then I think the best you can do is search around and get yourself a mono setup.

"He must be mad!" I hear you say, but no. If you search the second hand market you can get yourself a good CCD mono camera, filter wheel and SHO filter set cheaper than some of these top of the range Ha/Oiii & Oiii/Sii duo-band filter sets.

I managed to put together an Atik 428EX camera, Atik EFW2, Baader 7-8.5nm SHO and LRGB filter sets for just short of £800.  Sure, the sensor is smaller than my ASI294MC but I can create real SHO images or board-band for galaxies, and it doesn't really take any longer (apart from taking the flats ).

Just an alternative which may be worth considering.

 

[Gary Clayton]

51 minutes ago, Anthonyexmouth said:

What's the best bang for buck dual NB filter at the moment? preferably one with minimal halo issues. 

Difficult one this, I started off with the Optolong L-eXtreme and was mostly pleased with it apart from the halo issue which seemed particular bad so I ended buying the Antlia ALP-T "Gold" dual band 5nm filter and have not looked back, this was before the new L-Ultimate came out though. I am not sure that there is a cheap option if halo's are an issue for you.

[Elp]

I've had the lenhance and still own the lextreme, never seen an issue with it.

[Lee_P]

The L-Ultimate is great, but expensive. You might find this comparison I made of three dual NB filters useful.

[Anthonyexmouth]

2 hours ago, Gary Clayton said:

Difficult one this, I started off with the Optolong L-eXtreme and was mostly pleased with it apart from the halo issue which seemed particular bad so I ended buying the Antlia ALP-T "Gold" dual band 5nm filter and have not looked back, this was before the new L-Ultimate came out though. I am not sure that there is a cheap option if halo's are an issue for you.

The Antlia would be my choice if I was brave enough to spend that much on 2" of glass. I guess I really should. 

[Anthonyexmouth]

Anyone got any views on the STC dual band? Only review I've looked at showed that halos were minimal but it's got a bit of reduced transmission rate. 

[R26 oldtimer]

I think the best two bang for buck contenders are the L-extreme and the Idas NBZ. I had the l-extreme which didn't manifest any halos but moved to the NBZ with slightly broader band pass to use it with sub- f/3 optics.

[900SL]

You can be sure that the IDAS NBZ meets specification. Great filter for lower LP areas, I use it in Bortle 4-7

The Antlia is nominally tighter, I also have that, it's a good filter

I've never bought an Optolong Filter, because of reported halos

 

This test by Jim is useful

https://www.cloudynights.com/topic/797739-idas-filter-comparison-test-report/

Edited June 24, 2023 by 900SL

[Anthonyexmouth]

Well, I just bought an Askar Duo-band filter, not the colour magic magic one, the cheaper £199 one. Wondering if anyone has any feedback on this and also anyone created a filter profile for Pixinsight SPCC for this filter? 

Wondering if I made a mistake getting the cheaper one and should maybe return it and splash out for a colour magic one or the Antlia filter. 

https://www.firstlightoptics.com/askar-filters/askar-duo-band-narrowband-filter.html

[Budgie1]

The original Askar Duo-Band filter does suffer from the odd halo on stars, same as the L-eXtreme. It's a good filter for OSC NB imaging and does pull out good Ha & Oiii data. I have one and used it on a few of my images. The halo's can be cleaned up in post-processing with the CloneStamp after the stars have been removed.

I haven't done a profile for SPCC but use the White Reference "Photon Flux", 656.0nm for the Red channel and 500.7nm for the Green & Blue channels for an HOO image, all with a band width of 7nm.

See these threads for details and images:

 

Edited July 2, 2023 by Budgie1

[Anthonyexmouth]

7 minutes ago, Budgie1 said:

The original Askar Duo-Band filter does suffer from the odd halo on stars, same as the L-eXtreme. It's a good filter for OSC NB imaging and does pull out good Ha & Oiii data. I have one and used it on a few of my images. The halo's can be cleaned up in post-processing with the CloneStamp after the stars have been removed.

I haven't done a profile for SPCC but use the White Reference "Photon Flux", 656.0nm for the Red channel and 500.7nm for the Green & Blue channels for an HOO image, all with a band width of 7nm.

See these threads for details and images:

 

I did give it a go last night on the elephant truck and seems ok. Although session ruined with me auto focus issues. Are those options you mentioned in the spcc filter menu? 

[Budgie1]

3 minutes ago, Anthonyexmouth said:

Are those options you mentioned in the spcc filter menu? 

Yes, you need to tick the "Narrowband Filters Mode" to change the input.

[Anthonyexmouth]

Is the askar duo a 7nm bandpass? 

[Budgie1]

Yes, mine says 7nm on the label on the box.

[Anthonyexmouth]

32 minutes ago, Budgie1 said:

Yes, mine says 7nm on the label on the box.

Nothing on my label. 

[Budgie1]

I don't have anything on the filter itself but the case & out box both have it on there.

I should add that I got my Duo-Band just after they first came out, back in 2021, so they may have changed the packaging since then.

[Anthonyexmouth]

1 hour ago, Budgie1 said:

Yes, mine says 7nm on the label on the box.

That filter printing is the same as mine. 

[Bargy]

Don't want to hijack or anything, I'm really new to Imaging and I have a couple of the Optolong filters, but not done may targets yet.

I'm using the OSC 2600MC camera and I wanted to know - how do you know what filter to use on what target? For example I just put up my first post yesterday or the first image I have taken in the hobby, in which I used the L-Ultimate filter https://stargazerslounge.com/topic/411348-first-ever-dso-imaged-and-processed-ic1805-heart-nebula/

Everything is red with some yellow - but I saw a similar post where the same target ad blue's and green's in it as well - is that because I'm limited with my filter, or just the editor playing with colour schemes in post processing? I wondered if there was some kind of database online, or some way of looking at what type light a target object emits - so I can match that with the right kind of filter (if any) to make sure I don't block out stuff I would want to capture. 

Thanks

[Anthonyexmouth]

41 minutes ago, Bargy said:

Don't want to hijack or anything, I'm really new to Imaging and I have a couple of the Optolong filters, but not done may targets yet.

I'm using the OSC 2600MC camera and I wanted to know - how do you know what filter to use on what target? For example I just put up my first post yesterday or the first image I have taken in the hobby, in which I used the L-Ultimate filter https://stargazerslounge.com/topic/411348-first-ever-dso-imaged-and-processed-ic1805-heart-nebula/

Everything is red with some yellow - but I saw a similar post where the same target ad blue's and green's in it as well - is that because I'm limited with my filter, or just the editor playing with colour schemes in post processing? I wondered if there was some kind of database online, or some way of looking at what type light a target object emits - so I can match that with the right kind of filter (if any) to make sure I don't block out stuff I would want to capture. 

Thanks

You're probably seeing a narrowband image or someone has processed a osc image as a Hubble or Fornax image. Check out paulyman astro on YouTube for some good osc processing tips. 

[Budgie1]

11 hours ago, Bargy said:

Don't want to hijack or anything, I'm really new to Imaging and I have a couple of the Optolong filters, but not done may targets yet.

I'm using the OSC 2600MC camera and I wanted to know - how do you know what filter to use on what target? For example I just put up my first post yesterday or the first image I have taken in the hobby, in which I used the L-Ultimate filter https://stargazerslounge.com/topic/411348-first-ever-dso-imaged-and-processed-ic1805-heart-nebula/

Everything is red with some yellow - but I saw a similar post where the same target ad blue's and green's in it as well - is that because I'm limited with my filter, or just the editor playing with colour schemes in post processing? I wondered if there was some kind of database online, or some way of looking at what type light a target object emits - so I can match that with the right kind of filter (if any) to make sure I don't block out stuff I would want to capture. 

Thanks

So, the basic rule of thumb when using duo-band filters with OSC cameras is; Only use the duo-band filter (narrowband) on targets which mainly consist of Hydrogen Alpha & Oxygen III gases, so you're talking about Emission Nebula, such as the Heart (which you've imaged nicely ) California Nebula, North American Nebula .....etc. These filters are also good with Planetary Nebula like the Dumbbell and Super Nova remnants such as the Veil Nebula.

Where you don't want to use these filters is the like of star clusters, galaxies and Reflection Nebula, like the Iris, Ghost & the nebulosity around Pleiades because most of the light from these targets will be blocked by the filter. So, for these targets the best filter is a good UV/IR block filter, unless you have bad light pollution, in which case a suitable LP filter may be of use.

As for the different colours, as Anthony has said, this could be an image processed using the Hubble Pallet, as processing technique used initially for the Hubble Space Telescope images but now used for narrowband imaging. In narrowband imaging you use a mono camera with Ha, Oiii & Sii filters and when you process the image they are stacked using Sii for the Red channel, Ha for Green and Oii for Blue. This is called an SHO image.

You can use a similar technique with colour images and there are a few tutorials around for this, depending on the software you use.

Here's an SHO image I did of the centre of the Heart Nebula with my mono camera.

I hope that helps a little.