NGC 7000 Four Panels and 27 Hours

[HunterHarling]

Hi all, here is about 27 hours of Ha and Oiii data of NGC 7000. This is the largest deep sky panorama I've done yet, and was hard to put together in Pixinsight. Also, my ZWO filters are giving me halo problems, advise about removing the halos would be appreciated...

ASI 1600mm

FSQ106 ED

Ha: 25x400s per panel

OIII: 35x400s per panel

Total~26.7 hours

Thanks for looking

[Daniel-K]

That is lovely!! you could always clone out the halo's shouldn't be too difficult. 

[wimvb]

That's an excellent NA neb. 

Regarding removal of the halos, imho there really is only one long term solution: a Tak deserves more than cheap zwo filters. Consider investing in filters with good antireflective coatings. A short term solution is to create a mask and erode the halos. Have look here, a bit down the list

http://pixinsight.com.ar/en/processing-examples.html

[HunterHarling]

Thanks, Daniel and Wim. I tried cloning the halos, but it didn't turn out too well. 

6 hours ago, wimvb said:

a Tak deserves more than cheap zwo filters

I think you're right:) I'm really considering Astrodon, but if I go Astrodon I can't get the full set due to cost. Astronomic filters also look great though.

[wimvb]

27 minutes ago, HunterHarling said:

Thanks, Daniel and Wim. I tried cloning the halos, but it didn't turn out too well. 

I think you're right:) I'm really considering Astrodon, but if I go Astrodon I can't get the full set due to cost. Astronomic filters also look great though.

Astrodons are probably best. Good filters are expensive, because they're so hard to make right. The important characteristic of a filter isn't necessarily what it lets through, but rather what it blocks. That is, how much light outside the transmission band doesn't make it through the filter. Good filters are very efficient in blocking unwanted light. They also have a very high hardness and can withstand a fair amount of abuse. But they are expensive.

A good place to investigate various filters is probably astrobin.com. Look what results others achieve with filter brands that are of interest.

[gorann]

Very nice! I agree with Wim, you probably need better filters or live with the halos. It could be that Baader filters could be good enough, especially their new narrower ones. Good thing with the ASI1600 is that you could probably use 1.25" filters.

[HunterHarling]

6 hours ago, gorann said:

Very nice! I agree with Wim, you probably need better filters or live with the halos. It could be that Baader filters could be good enough, especially their new narrower ones. Good thing with the ASI1600 is that you could probably use 1.25" filters.

Yes, fortunately I can use 1.25" filters😂 Would be very expensive if I needed 2 inch, even for brands other than Astrodon. Amazing how much a small circle of glass costs...

[wimvb]

4 hours ago, HunterHarling said:

Amazing how much a small circle of glass costs...

Worse than that. The glass isn't that expensive. It's the thin layers of (most likely) quartz and toothpaste whitener on that glass and only a few micrometers thick, that cost.

Good nb filters are made by depositing alternating layers of silicon dioxide (quartz) and titanium dioxide (also used to make toothpaste and paint look white) or zirconium oxide (a ceramic material used in dental caps).

[alan potts]

Halos or not it is a superb image, I keep looking at this and wondering about trying my Canon F2.8 300mm on it with a camera, should be about wide enough but I don't have any filters, only a visual Olll filter and H beta, both of which I imagine are not much good.

Alan

[gorann]

10 hours ago, HunterHarling said:

Yes, fortunately I can use 1.25" filters😂 Would be very expensive if I needed 2 inch, even for brands other than Astrodon. Amazing how much a small circle of glass costs...

This one could be worth a try and the cost is not astronomical, or at least do some googling to see if someone has experience with it. I think maybe Olly @ollypenrice has tried it (or at least talked about getting one).

https://www.firstlightoptics.com/narrowband/baader-ultra-narrowband-45nm-oiii-filter.html

[carastro]

Very nice image.

I must confess that once I cheated with halos and this is what I did.  (I think it was when i did IC63)

Take the Ha and Oiii mono images - in the situation that the Ha has no halo and the Oiii does.

Register the images to each other which you will do anyway for combining.  I placed the Oiii image over a copy of the Ha image and rubbed out the Oiii star and Halo and flattened giving an Oiii image without the halos.

Then combined the new Oiii image with the original Ha image. 

Bit cheaper than buying Astrodon filters.

Interestingly I don't recall having to do this since, don't know why and that was 4 years ago. 

Carole 

 

Edited August 17, 2019 by carastro

[ollypenrice]

1 hour ago, gorann said:

This one could be worth a try and the cost is not astronomical, or at least do some googling to see if someone has experience with it. I think maybe Olly @ollypenrice has tried it (or at least talked about getting one).

https://www.firstlightoptics.com/narrowband/baader-ultra-narrowband-45nm-oiii-filter.html

The new Baader OIII is not available yet. I have one on order but it isn't expected till October (which will be an expensive month because my new motorcycle is supposed to arrive then as well!)

A word of caution: are we sure this is the filters? Wasn't there some talk of the camera being prone to this issue? I'm maybe half-remembering a thread here.

Anyway it's a very attractive NAN.

If you think Astrodons are expensive, try one of these!

Soooo handy because it can isolate any wavelength down to the narrowest range from anywhere in the spectrum. Unfortunately it was too large to fit in my drawtube since it was designed to fit inside the altitude bearing of the VLT...

lly

[DaveS]

  

I had halo problems with my first set of Baader NB filters, cured by the simple, if expensive, expedient of ditching the Baaders and buying a set of 3nm Astrodons. At the time they were "only" £385 each. now they are silly money.

[ollypenrice]

3 minutes ago, DaveS said:

  

I had halo problems with my first set of Baader NB filters, cured by the simple, if expensive, expedient of ditching the Baaders and buying a set of 3nm Astrodons. At the time they were "only" £385 each. now they are silly money.

Ha as well as OIII? My Baader OIIIs have had haloes (like my Astronomiks) but the Ha filters have always been fine. (In several examples.)

I'd have Astrodons in a world of financial plenty for sure!

Olly

[DaveS]

I think the Baader HII was OK, but I wanted an homogeneous set. I do use the Baader HII in an alternative HaLRGB set with ZWO LRGB filters on an ASI1600 set up.

[HunterHarling]

4 hours ago, carastro said:

placed the Oiii image over a copy of the Ha image and rubbed out the Oiii star and Halo and flattened giving an Oiii image without the halos.

This seems like it will work... I'll give it a try.

 

2 hours ago, ollypenrice said:

My Baader OIIIs have had haloes (like my Astronomiks) but the Ha filters have always been fine. (In several examples.)

Same with me. At least for my ZWO set, the OIII is always the one to give halos.