NGC 6960 Western Veil Nebula

[Hughsie]

Went a bit mad over the Bank Holiday Weekend imaging this target. Spent three nights overall on it. I have posted the first nights work already but was not happy with the framing as I knew there was more to see below the broomstick.

The second night, 24 and 25 August, I felt was better framed. However, I went a bit mad as this was only my second narrow band session and was I playing with the filter wheel like a loon! I was trying them all Ha, Oiii and Sii, I even popped a few IR/UV subs in for good measure. You know if I could have wrapped cling film around it I would have shot that too....and probably got a better image.

Anyway, with complete disregard as to what the target needed to best show it I realised later (not even on the third night when I was trying sandpaper and cardboard in the filter wheel), that NGC 6960 looks great as an HOO image. Fortunately I had some subs;

Ha 16 x 300s gain 139

Oiii 20 x 300s gain 139

Both captured with the ZWO ASI1600mm Pro Cooled at -15c and a William Optics Z103 mounted on a HEQ6R Pro.

Enjoy and any feedback welcome.

John

 

 

 

Edited September 9, 2019 by Hughsie
Re-processed image, labelled and aligned N/S

[souls33k3r]

That's really awesome. I'm also surprised to see that the bright star did not have the age old chequered problem. A lot of us suffer from this issue. What filter did you use if you don't mind me asking? 

[geoflewis]

Absolutely gorgeous, well worth the 3 nights I say....

Geof

[Hughsie]

6 minutes ago, souls33k3r said:

That's really awesome. I'm also surprised to see that the bright star did not have the age old chequered problem. A lot of us suffer from this issue. What filter did you use if you don't mind me asking? 

I used the Baader Ha 7nm and Oiii 8.5nm purchased from our good friends at FLO.

Personally, I would like to see a softer image and try as I may I couldn’t remove most of the small stars.

Spent 6 hours this morning post integration processing and just had to stop. I will come back to it in a few days as I have it saved as a PixInsight project so I can choose where I want to start from.

 

john

[Craney]

Nice job.     

I've yet to get into multi-day exposures.   I like to see a "result" the next day.      Three clear nights within a period of 2 weeks is rare.

This is a really vibrant example and may lead me over the divide.

Sean.

[teoria_del_big_bang]

Really nice. You definitely made the best of what was probably one of the best few nights in a row viewing for a while 🙂 

Steve

[Hughsie]

48 minutes ago, Craney said:

Nice job.     

I've yet to get into multi-day exposures.   I like to see a "result" the next day.      Three clear nights within a period of 2 weeks is rare.

This is a really vibrant example and may lead me over the divide.

Sean.

If you get the weather Sean I say go for it. 

I use APT and saved the ra/dec settings of my second night but looking at my third night I may be a bit off target.

Having said that I looked in Astrobin and saw an imager who had...... wait for it ..... SEVENTY FIVE HOURS of data.

Well, you know what I say to that sort of commitment?

I don’t wear thermals in winter, that’s what I say 😝

John

[Craney]

8 minutes ago, Hughsie said:

   .....SEVENTY FIVE HOURS of data......

I know that's quite something.  More than I have in a year.      

For me to accumulate this much data I would seriously have to be careful about stars  actually coming to the end of their Main Sequence  lives before I got t on to the  Oiii  filter.

[Hughsie]

1 minute ago, Craney said:

For me to accumulate this much data I would seriously have to be careful about stars  actually coming to the end of their Main Sequence  lives before I got t on to the  Oiii  filter.

I would have to be careful of the wife first!

[Adam J]

3 hours ago, souls33k3r said:

That's really awesome. I'm also surprised to see that the bright star did not have the age old chequered problem. A lot of us suffer from this issue. What filter did you use if you don't mind me asking? 

I would not say that star is bright enough to cause that issue in narrow band.

[Hughsie]

2 minutes ago, Adam J said:

I would not say that star is bright enough to cause that issue in narrow band.

That will be the cling film kicking in!

[Adam J]

4 hours ago, Hughsie said:

Went a bit mad over the Bank Holiday Weekend imaging this target. Spent three nights overall on it. I have posted the first nights work already but was not happy with the framing as I knew there was more to see below the broomstick.

The second night, 24 and 25 August, I felt was better framed. However, I went a bit mad as this was only my second narrow band session and was I playing with the filter wheel like a loon! I was trying them all Ha, Oiii and Sii, I even popped a few IR/UV subs in for good measure. You know if I could have wrapped cling film around it I would have shot that too....and probably got a better image.

Anyway, with complete disregard as to what the target needed to best show it I realised later (not even on the third night when I was trying sandpaper and cardboard in the filter wheel), that NGC 6960 looks great as an HOO image. Fortunately I had some subs;

Ha 16 x 300s gain 139

Oiii 20 x 300s gain 139

Both captured with the ZWO ASI1600mm Pro Cooled at -15c and a William Optics Z103 mounted on a HEQ6R Pro.

Apologies for the Harry Potter tag, its just when I look at this image I get the impression the witches broom has shot across the bottom from left to right then done a 180 and is heading back in the opposite direction. Not exactly a Nimbus 2000, its a bit more like Triggers!

Enjoy and any feedback welcome.

John

 

Very nice, i think you need to reduce the spacing on your corrector though only slightly.

[souls33k3r]

12 minutes ago, Adam J said:

I would not say that star is bright enough to cause that issue in narrow band.

Trust me it is. I guess the fov is not narrow enough to notice this. 

[Hughsie]

9 minutes ago, Adam J said:

Very nice, i think you need to reduce the spacing on your corrector though only slightly.

Thank you Adam. I have ready many of your responses on here and welcome your feedback.

You are correct, I have been struggling to get the back focus correct and this was as close as I have got so far. I have been playing with the Flat 6AII on the WO Z103 and got the spacing right at 4.6mm but there are still some stars which are elongated as you have identified.

I now have an adjustable spacer and (hopefully) it will allow me to establish the correct B/F and then put the right permanent parts in place to correct this.

But a question for you. With the filters in play do I need to account for the thickness of the filter glass too? I understand this to be 0.7mm on Baader NB filters.

Thank you in advance,

John

 

 

[Adam J]

24 minutes ago, Hughsie said:

Thank you Adam. I have ready many of your responses on here and welcome your feedback.

You are correct, I have been struggling to get the back focus correct and this was as close as I have got so far. I have been playing with the Flat 6AII on the WO Z103 and got the spacing right at 4.6mm but there are still some stars which are elongated as you have identified.

I now have an adjustable spacer and (hopefully) it will allow me to establish the correct B/F and then put the right permanent parts in place to correct this.

But a question for you. With the filters in play do I need to account for the thickness of the filter glass too? I understand this to be 0.7mm on Baader NB filters.

Thank you in advance,

John

 

 

Thanks I hope I talk sense the majority of the time at least. 

Baader use 2mm thick glass on their smaller filters. So you need to add 0.7mm in theory. However, you also have other glass in play (sensor cover glass and optical window), the camera sensor position is always a fraction different between cameras etc. So use the distance recommended by WO for your scope as a starting point as opposed to gospel. From the direction of the distortion you can see its too much spacing as opposed to too little. I would take 0.5mm off and test and then if its still out another 0.5mm etc. A digital caliper is essential if you really want things spot on you cant accurate adjustments without one.

Adam

[Adam J]

1 hour ago, souls33k3r said:

Trust me it is. I guess the fov is not narrow enough to notice this. 

That would make sense all i know is that I dont see it on that star with my 130PDS at 650mm F5 and so I would not expect to see it on smaller apertures / focal lengths either.

But its not really FOV so much as intensity as stars being point sources scale in brightness with aperture irrespective of f-ratio.

Edited September 6, 2019 by Adam J