OSC NB Filter

[Grifflin]

Hi All

So I'm on a journey with AP and, for the moment, have chosen to go down the OSC route (for now 😃).  I currently have a ZWO 294MC and have really enjoyed the images I get from it.  I think that the next step for me is to invest in a NB multi band filter.  I already have a L Pro and a UV/IR cut so a NB multi band feels like a logical step.  This is my thinking....and please feel free to put me right, I am fairly new to this:

- Galaxies / reflection nebula:  UV/IR cut or L-Pro depending where in the sky they are (Bortle 4/5 but with noticeable light "domes" in some areas)

- Emission nebula: UV/IR cut if high otherwise NB filter....or would a NB filter be better for both....or neither?

- How effective is a NB multi band against moonlight?

I have two questions:  a) am I diving down the wrong route here (mono is in the future but OSC for now 😔) and  b) if money was not a particular object then which NB multi band filter would you go for?

Really grateful for your thoughts and experiences and please feel free to put me right if I'm off track.  Like I said...its a journey.

Neil

[Budgie1]

I also have the ASI294MC Pro and use it with the 1.25" Optolong L-eXtreme filter screwed into the filter holder in the 11mm spacer on the front of the camera.

I use this for emission nebula and bought it mainly for when the Moon is bright. I'm lucky in that I live in a Bortle 2 area but as such the Moon does create a more noticeable issue when full. Even with the L-eXtreme filter installed I still don't image close to the Moon but it does allow me to image during the full Moon period.

I think a good illustration of what the duel NB filter does is in these two images of the Horse Head & Flame which I took back in March.

The top one is with just a UV/IR cut filter. Notice the amount of nebulosity visible from NGC2023 in the centre of the image and the lack  of Ha data in the red background to the Horse Head. 

Now have a look at the bottom image and see what the L-eXtreme filter has done to those two parts of the image, as well as the colour of the Flame Nebula. You'll also notice the stars are very much reduced in this image as well.

Are you diving down the wrong route? No, not if you feel it will benefit your imaging and as long as you use the filter on the right targets.

Which filter? The L-eXtreme seems to have the best reputation of the duel-band filters but others also rate the L-eNhance as well because it's not as aggressive as the L-eXtreme and also lets through Hb.

I hope that helps and I'm sure others will give their experience with the likes of the Tri-Band & Quad-Band filters also available.

[Stuf1978]

I second the L-eXtreme, I'm using the 2" version on my ZWO ASI 294MC Pro and it really does work wonders from my Bortle 8 location. I've previously used the L-eNhance before I moved over to the ZWO camera with a modified dslr and although good the L-eXtreme is significantly better. However, as Budgie1 mentioned try and choose your targets carefully as I've found these filters are not suitable for every target and can kill the detail in certain objects. Dual narrow band filters for emmision nebula and UV/IR cut for galaxies and reflection nebula and you'll be fine  This was taken with the 294MC Pro, WO Redcat and the Optolong L-eXtreme from my bortle 8 garden:

 

[tomato]

This was taken with a QHY268C OSC and a IDAS NBX dual band filter, specifically chosen to better accommodate the focal ratio of the RASA8. 
 

The NBX suffered from star halos and has since been replaced with the NBZ filter.

[Grifflin]

Thank you and sorry for the delay in replying.

@Budgie1 Cracking images and a really good comparison.  This is a target I have on my list for the Winter.  Got to say the L-Extreme definitely pulls out more detail.  I have heard that it can create halos and I can see this but is this only for really bright stars and how much can be fixed in post?

@Stuf1978 Love this and I took this target the other week.  Clearly pulling out a lot more detail than I did.  What was your integration time on that?

@tomato  Ok...wow...was that like 1 x 3min sub with the RASA? So Im imaging between f5.6 and f10.  Would the slower scopes create issues here?

Also, thank you for confirming my approach to what to use when.

So far it looks like the L-Extreme might have it but still interested in the L-Enhance as my light pollution isn't too bad.  Also is there any value in looking at tri or even quad band filters?

Neil

[Stuf1978]

1 hour ago, Grifflin said:

Thank you and sorry for the delay in replying.

@Budgie1 Cracking images and a really good comparison.  This is a target I have on my list for the Winter.  Got to say the L-Extreme definitely pulls out more detail.  I have heard that it can create halos and I can see this but is this only for really bright stars and how much can be fixed in post?

@Stuf1978 Love this and I took this target the other week.  Clearly pulling out a lot more detail than I did.  What was your integration time on that?

@tomato  Ok...wow...was that like 1 x 3min sub with the RASA? So Im imaging between f5.6 and f10.  Would the slower scopes create issues here?

Also, thank you for confirming my approach to what to use when.

So far it looks like the L-Extreme might have it but still interested in the L-Enhance as my light pollution isn't too bad.  Also is there any value in looking at tri or even quad band filters?

Neil

Thanks, total integration was 72 x 300 second subs (so 6 hours) 👍

[tomato]

2 hours ago, Grifflin said:

 

@tomato  Ok...wow...was that like 1 x 3min sub with the RASA? So Im imaging between f5.6 and f10.  Would the slower scopes create issues here?

I wish! That’s 20 x 3 min so one hour of integration. The IDAS NBZ filter is well suited to the steep light cone of the F2 RASA, but at your proposed focal ratio, you have no such restriction on filter choice.

[powerlord]

+1 for L-extreme. I've for the 1.25 and the 2". I pretty much never osc without them now. 1.25 with the asi533, 2" as aperture reducer on front of lens with Canon 6d.

Awesome filter.

[Budgie1]

2 hours ago, Grifflin said:

 

@Budgie1 Cracking images and a really good comparison.  This is a target I have on my list for the Winter.  Got to say the L-Extreme definitely pulls out more detail.  I have heard that it can create halos and I can see this but is this only for really bright stars and how much can be fixed in post?

The L-eXtreme has pulled out more detail but it has also removed the finer detail from the dust visible in the first image below the Horse Head (mid to bottom right in the image). So it's only the Ha detail that's been enhanced.

I think better focus would help with the first image but when I get the chance to do this target again I think I'll reduce the exposure time to try and control the large star. These were both taken with 2 minute subs so possibly a combination of 2 and 1 minute subs may tame Alnitak. Even dropping to 1 minutes subs but lots of them may help,

[Lee_P]

+1 for L-eXtreme. I've got lots of examples here, all from Bortle 8: http://urbanastrophotography.com/index.php/gallery/

This is my fave so far:

[Grifflin]

36 minutes ago, Lee_P said:

+1 for L-eXtreme. I've got lots of examples here, all from Bortle 8: http://urbanastrophotography.com/index.php/gallery/

This is my fave so far:

Ok....yep...that'll do  😉.  How much time did you have yo put into this?

Checking out your website now!

Edited September 17, 2021 by Grifflin

[Lee_P]

41 minutes ago, Grifflin said:

Ok....yep...that'll do  😉.  How much time did you have yo put into this?

Checking out your website now!

480 x 120 seconds, so 16 hours total for that shot. More info: http://urbanastrophotography.com/index.php/2021/06/10/the-elephants-trunk-nebula/

[CloudMagnet]

For me with limited imaging time, the ease of setting up OSC with my L-eNhance filter is the best way. Mono might give better results (up for debate) but I prefer not to worry about different filters, flats etc... and just do everything at once. It is also possible to create Hubble Palate images or your traditional "red" nebula shots. I wouldn't say that mono is the future as OSC with the dual/tri filters are definitely comparable with Mono images- and you have the flexibility to process your images in different ways.

The moon still will have an effect on dual narrowband filters, but nothing as major as shooting broadband, I wouldnt worry about this too much unless you are looking to get APOD or similar.

This is one of my recent images, done with ZWO 071 MC Pro with L-eNhance as a two panel mosaic with about 5hrs total exposure. Processed as Hubble style and "normal" colours for comparison

 

 

Edited September 17, 2021 by CloudMagnet

[powerlord]

10 hours ago, CloudMagnet said:

For me with limited imaging time, the ease of setting up OSC with my L-eNhance filter is the best way. Mono might give better results (up for debate) but I prefer not to worry about different filters, flats etc... and just do everything at once. It is also possible to create Hubble Palate images or your traditional "red" nebula shots. I wouldn't say that mono is the future as OSC with the dual/tri filters are definitely comparable with Mono images- and you have the flexibility to process your images in different ways.

The moon still will have an effect on dual narrowband filters, but nothing as major as shooting broadband, I wouldnt worry about this too much unless you are looking to get APOD or similar.

This is one of my recent images, done with ZWO 071 MC Pro with L-eNhance as a two panel mosaic with about 5hrs total exposure. Processed as Hubble style and "normal" colours for comparison

 

 

How are processing those ? Really like the look. Hubble pallette never comes out like that when I try it.

[CloudMagnet]

3 hours ago, powerlord said:

How are processing those ? Really like the look. Hubble pallette never comes out like that when I try it.

 

The "red" image was just done in photoshop whereas the Hubble style was done in Pixinsight, I basically followed this tutorial:

https://www.youtube.com/watch?v=OVb1_Nqcs5I

The colours can be temperamental- it can take a fair amount of playing around with the curves and saturation in each channel to get the most out of it. They can look quite washed out when you start out.

[licho52]

I am using the L-Extreme and it's great, however there are 2 things that come with it, first, to really get star colors it's important to capture an additional broadband stack with color stars to put in place of l-extreme's star field.  Second, some stars are just too bright and their halo is can only be removed by hand using Photoshop or another program like that.  Sadr or Alnitak come to mind.

I essentially throw out all stars that come from l-extreme.  I don't even care so much if there's some frame with elongated stars, they get removed either way.

[Lee_P]

On 21/09/2021 at 08:57, licho52 said:

I am using the L-Extreme and it's great, however there are 2 things that come with it, first, to really get star colors it's important to capture an additional broadband stack with color stars to put in place of l-extreme's star field.  Second, some stars are just too bright and their halo is can only be removed by hand using Photoshop or another program like that.  Sadr or Alnitak come to mind.

I essentially throw out all stars that come from l-extreme.  I don't even care so much if there's some frame with elongated stars, they get removed either way.

Putting broadband stars into an L-eXtreme image is something I want to try but haven't gotten round to doing. I'd be interested in seeing any examples you have.

[licho52]

On 26/09/2021 at 23:23, Lee_P said:

Putting broadband stars into an L-eXtreme image is something I want to try but haven't gotten round to doing. I'd be interested in seeing any examples you have.

This is unfinished both in nebula(adding 5-6 more hours here) and star layers (new scope, was still looking for the right flattner setting, not quite there at the time of this shot), but I set this up to make sure I can control Sadr and not have it ruin this field.  Now that I was able to replace all stars from L-Ex in a satisfactory manner, I know this is worth pursuing further.

Sadr with L-Extreme absolutely ruins this field, you can see many examples of people who just sort of leave it there which IMO is so ugly it mars the picture completely.  Note that StarNet leaves remnants of halos and how far one goes in manually fixing them is a personal choice I think, my rule is that if I don't see it without zooming, it can stay.  There's only so many hours in a day...

Edited September 28, 2021 by licho52

[licho52]

One more thought about processing with L-Extreme: one basically is getting ready for mono processing as we end up with H, O and RGB layers.  In some ways I feel I should just go for 2600MM....as there's hardly any ONE SHOT left in my OSC....

2 things are stopping me: the cost of the wheel and finding proper filter sets and just how good the 2600MC is at broadband Gain 0 setting.

[GoldTop57]

I'm using both the L-eNhance and L-eXtreme with the ASI294MC pro - I've gone with an OSC because of the limited imaging time here in the UK.

[adyj1]

1 hour ago, GoldTop57 said:

I'm using both the L-eNhance and L-eXtreme with the ASI294MC pro - I've gone with an OSC because of the limited imaging time here in the UK.

I've been trying to work out which one to plump for... When do you use the l-enhance over the l-extreme? 

[GoldTop57]

I've no hard and fast rules as to which filter to use I'm afraid. You can search Astrobin to compare images taken with each filter - it might sway you one way or the other.

[Sp@ce_d]

This is 32x300 of an IDAS-NBZ on a ASI2600MC with NO dithering or calibration whatsoever.. its a raw test and quick process of first light with an Esprit80 back in Feb.. purely for my own interest it's not a process I'd do with such limited data for a final result but gives you an idea. Not had time/skies to do any proper ones with this camera since. I've also recently got the Mono version (2600MM) & I have to say I'm still in the Mono camp if you have the time & patience..(I'll forgo the argument that Mono is quicker anyway) none the less the OSC is very impressive with the IDAS-NBZ. I've used various IDAS LP filters over the years & been impressed. Not tried Optolong. 

EDIT: Sorry just checked the headers, these were actaully 180s (3min) exposures, so 96 mins in total.

Edited September 29, 2021 by Sp@ce_d
Wrong exposure time quoted..