Trunk in Ha

[Allinthehead]

Hi all. This is one that needs little introduction. This is my first attempt at it and i'm glad i went for it as there's so much going on here and with the moon around it's a nice bright target.

Imaging telescope: Takahashi Epsilon 130d

Imaging camera: ZWO ASI1600MM-Cool

Mount:SkyWatcher AZ EQ6

Software:Sequence Generator Pro Seqence Generator Pro

Filter:Astrodon 5nm Ha

Resolution: 4611x3489

Dates: April 24, 2018,  April 25, 2018

Frames: 
Astrodon 5nm Ha: 50x300" (gain: 129.00) -20C 
Astrodon 5nm Ha: 35x300" (gain 0) -20C

Integration: 7.1 hours

Darks: ~50

Flats: ~50

Bias: ~50

Avg. Moon age: 9.61 days

Avg. Moon phase: 72.71%

Bortle Dark-Sky Scale: 4.00

Astrometry.net job: 2034372

RA center: 324.566 degrees

DEC center: 57.504 degrees

Pixel scale: 1.826 arcsec/pixel

Orientation: 359.825 degrees

Field radius: 1.466 degrees

Locations: Back Garden, Cork, Ireland

Jpg

Richard.

[MarsG76]

Thats a fantastic result.. I see that the ZWO 1600 is delkivering a good astro cam.. I'm considering getting this cameras and am wondering whether the expanse will improve my images substantially when comparing to what I'm getting now.

 

[adyj1]

Very nice. My phone nearly melted downloading the full picture, but I had to see it ☺ 

[Allinthehead]

3 hours ago, MarsG76 said:

Thats a fantastic result.. I see that the ZWO 1600 is delkivering a good astro cam.. I'm considering getting this cameras and am wondering whether the expanse will improve my images substantially when comparing to what I'm getting now.

 

Thanks Mars. For the money it's a great camera. If i was in the market i'd probably hold off and see what's coming down the line as it has issues around bright stars.

3 hours ago, adyj1 said:

Very nice. My phone nearly melted downloading the full picture, but I had to see it ☺ 

Thanks. Hope it was worth it.

[MarsG76]

20 minutes ago, Allinthehead said:

Thanks Mars. For the money it's a great camera. If i was in the market i'd probably hold off and see what's coming down the line as it has issues around bright stars.

Thanks for the info/heads up....

[cfpendock]

I have seen many really good images of this in narrowband using various palettes, but always I prefer just the Ha.  Excellent result!  Especially considering the moon.  I think you have justified the Astrodon filter....

Chris

[Allinthehead]

47 minutes ago, cfpendock said:

I have seen many really good images of this in narrowband using various palettes, but always I prefer just the Ha.  Excellent result!  Especially considering the moon.  I think you have justified the Astrodon filter....

Chris

Thanks Chris. Now i have to talk myself out of the 3nm.

[adyj1]

7 hours ago, Allinthehead said:

Thanks. Hope it was worth it.

Absolutely ☺ 

[newbie alert]

Superb image.. fantastic equipment...

And I really should visit cork someday 

[Allinthehead]

4 hours ago, newbie alert said:

Superb image.. fantastic equipment...

And I really should visit cork someday 

Thanks. If you do West Cork and Kerry is stunning. There's a dark sky reserve in Kerry too. Cloud is an issue there however.

[Rodd]

Nice FOV--and the small pixels retain the resolution.  Nice.

Rodd

[Allinthehead]

18 hours ago, Rodd said:

Nice FOV--and the small pixels retain the resolution.  Nice.

Rodd

Thanks Rodd.

[Rodd]

I think this target should be called the Dementor Nebula.  The Dementor is the black beasty swooping down from the top of the frame.  

Rodd

 

BTW--copuld you post the 2 different gain stacks--I have no real idea how gain effects the data.  I see you used 2 gains.  Any difference?

[Allinthehead]

3 hours ago, Rodd said:

I think this target should be called the Dementor Nebula.  The Dementor is the black beasty swooping down from the top of the frame.  

Rodd

 

BTW--copuld you post the 2 different gain stacks--I have no real idea how gain effects the data.  I see you used 2 gains.  Any difference?

Hi Rodd. I wanted to see the difference in individual frames and stacks between 0 and unity. I must walk the dog but when i return i'll post them.

[swag72]

Lovely - Looks super in mono...... great detail and brilliant processing   

[Allinthehead]

1 hour ago, swag72 said:

Lovely - Looks super in mono...... great detail and brilliant processing   

Thanks Sara appreciate that.

[Allinthehead]

Hope this helps @Rodd. I'm glad you asked me to do it as i've never bothered with a direct comparison.

Gain 139 33 subs at 300 seconds Fully Calibrated auto stretched

Gain 0 33 subs 300s Calibrated

 

Combined auto stretch

Gain 139 300s single sub Calibrated

Gain 0 300s Calibrated

 

 

 

 

[Rodd]

1 hour ago, Allinthehead said:

Hope this helps

Thanks!  But I am not sure!!  Wow--there is a huge difference between single subs of different gains, but when 33 subs are stacked--the difference goes away--at least on my screen at normal viewing.  Is that what you found as well?  If that's true--what would be the advantage of the 0 gain?  Both 0 and 139 seem to generate identical stacks using eth same number of subs with the same exposure times

[Allinthehead]

If you blink between the two stacks you can see a big difference. I'm leaning towards using unity gain from now on. The advantage of 0 gain is smaller stars and higher dynamic range. The advantage of unity i suppose going by these stacks from my eye is brighter better detail.

[Rodd]

8 hours ago, swag72 said:

and brilliant processing

Considering its an auto stretch

[swag72]

5 hours ago, Rodd said:

Considering its an auto stretch

I'm not judging how anyone does their processing or what tools they use - In my opinion the processing here is very effective and I like it very much...... hence my comment.... and since my comment was made before it was said that it was an auto stretch....... Your point exactly is? 

[Allinthehead]

5 hours ago, Rodd said:

Considering its an auto stretch

It's not an auto stretch. The cheek. The images i posted for you Rodd are all auto stretches. Which i stacked individually just for you by the way. My image at the top of the thread is processed by me. Click on the image so it becomes a tab of it's own then do the same for the combined auto stretch and you'll see the difference. Maybe i shouldn't bother processing anymore and just auto stretch if people can't see the difference. Could save hours

[Rodd]

5 hours ago, swag72 said:

I'm not judging how anyone does their processing or what tools they use - In my opinion the processing here is very effective and I like it very much...... hence my comment.... and since my comment was made before it was said that it was an auto stretch....... Your point exactly is? 

 

[Rodd]

4 hours ago, Allinthehead said:

It's not an auto stretch. The cheek. The images i posted for you Rodd are all auto stretches. Which i stacked individually just for you by the way. My image at the top of the thread is processed by me. Click on the image so it becomes a tab of it's own then do the same for the combined auto stretch and you'll see the difference. Maybe i shouldn't bother processing anymore and just auto stretch if people can't see the difference. Could save hours

Sorry Richard....my mistake......... 

[Allinthehead]

7 minutes ago, Rodd said:

Sorry Richard....my mistake......... 

No worries Rodd.