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Live Stacks January 5 and 6 2019

Posted: Mon Jan 07, 2019 12:34 am
by BlackWikkett
Hi Folks,

My first moonless clear night of the year! We've been really swamped with rain in in the southeast of the US so having such a clear night was a very nice change.

All images were live stacked in SharpCap,

My equipment is RC 6 inch, ZWO ASI294 MC Pro camera, iOptron Cem60 mount, 50mm Stellarvue guide scope ZWO ASI120MM guide camera + PHD2

All images use the same settings: 30 sec exposure, 300 gain, 10 offset(brightness,) cooler at -15 c (these settings work well for this scope & camera)
Used master dark with 25 subs and master flat with 50 subs. If you follow the image link to flickr you can see camera settings file created in SharpCap.

Since the images are live stacks without any additional processing you'll see some stacking artifacts on the edges and a satellite trail or two in some images.

Thanks for having a look
-Wikkett

ImageNGC 281 Pacman Nebula Stack_88frames_2640s_WithDisplayStretch by Black Wikkett, on Flickr

ImageM33 Triangulum Galaxy Stack_81frames_2430s_WithDisplayStretch by Black Wikkett, on Flickr

ImageNGC2024 Flame Nebula & B33 Horsehead Nebula Stack_57frames_1710s_WithDisplayStretch by Black Wikkett, on Flickr

ImageNGC2359 Thor's Helmet Stack_38frames_1140s_WithDisplayStretch by Black Wikkett, on Flickr

ImageM50 Open Cluster Stack_38frames_1140s_WithDisplayStretch by Black Wikkett, on Flickr

ImageM63 Sunflower Galaxy Stack_66frames_1980s_WithDisplayStretch by Black Wikkett, on Flickr

ImageSH2-302 Snowman Nebula Stack_40frames_1200s_WithDisplayStretch by Black Wikkett, on Flickr

ImageIC2177 Region Stack_68frames_2040s_WithDisplayStretch by Black Wikkett, on Flickr

ImageIC2177 Seagull Nebula Stack_61frames_1830s_WithDisplayStretch by Black Wikkett, on Flickr

ImageM51 Whirlpool Galaxy Stack_216frames_6480s_WithDisplayStretch by Black Wikkett, on Flickr

ImageM13 Hercules Globular Cluster Stack_33frames_990s_WithDisplayStretch by Black Wikkett, on Flickr

ImageM92 Globular Cluster Stack_30frames_900s_WithDisplayStretch by Black Wikkett, on Flickr

ImageM5 Globular Cluster Stack_20frames_600s_WithDisplayStretch by Black Wikkett, on Flickr

Re: Live Stacks January 5 and 6 2019

Posted: Tue Jan 08, 2019 12:18 am
by roelb
Terrific!

Re: Live Stacks January 5 and 6 2019

Posted: Tue Jan 08, 2019 7:34 pm
by BlackWikkett
Thanks roelb

Was a fun night and had several folks watching live at NSN.

-Wikkett

Re: Live Stacks January 5 and 6 2019

Posted: Tue Jan 08, 2019 9:03 pm
by turfpit
A good night's work Wikkett. Some nice detail on the M51.

Dave

Re: Live Stacks January 5 and 6 2019

Posted: Wed Jan 09, 2019 8:22 am
by BlackWikkett
Thanks Dave!

Since Robin has tweaked flats in live stacking along with many lessons learned in the process of testing many different methods. The live stack feature of SharpCap is really showing what's possible with minimal exposure times, white balance and some stretching.

-Wikkett

Re: Live Stacks January 5 and 6 2019

Posted: Wed Jan 09, 2019 10:20 pm
by nexusjeep
Very impressive just started playing with live stacking and the brain function so will now have to experiment more, that's the fun with astrophotography you are always learning and can always improve. The only downside is being monochrome it takes me a bit longer to get to a colour image.

Cheers
Nick

Re: Live Stacks January 5 and 6 2019

Posted: Thu Jan 10, 2019 2:47 am
by SkyThrall
BTW, what focal length is your RC-6 operating at?

Re: Live Stacks January 5 and 6 2019

Posted: Thu Jan 10, 2019 8:35 pm
by BlackWikkett
Thanks nexusjeep!

focal length is 1031 mm f/6.79 using the Astro-Physics CCDT67. Standard focal length is 1360 f/9

-Wikkett

Re: Live Stacks January 5 and 6 2019

Posted: Sun Jan 13, 2019 8:23 am
by donstim
Fantastic images!

I hope you don't mind answering some very basic questions about the Live Stacking technique you used.
1. Are you making any changes to the histogram settings (black, mid, and white levels) while the stack is building?
2. If so, when do you stop making such changes?
3. How do you determine when to end the stacking and save the image?
4. Do you save any intermediate stacks? If so, I would be interesting in seeing the difference between the intermediate stack(s) and the final one for any of these images.

Thanks,
Don

Re: Live Stacks January 5 and 6 2019

Posted: Sun Jan 13, 2019 3:15 pm
by BlackWikkett
Thanks Don,

1. Once you have 2 images stacked in Live Stack the main histogram and color / saturation controls become active. I do an initial auto stretch and auto white balance for color. This makes the object visible and get color close. Now adjust color so the peaks for R G B align in the small display histogram. Apply an auto stretch in display histogram. Since this is being done on the fly i'll keep adjusting these settings as more data comes in. Also add noise reduction and sharpening as or if needed. This is all really to personal taste and in my case I'm looking for least noise and most signal, what in my mind makes a pretty picture.

2. Changes are constant some nights you get lucky and depending on object less is more

3. Again this is to taste and if you want to eek out that last little bit on an object. More below

4. Not currently, I used to save individual raw frames for possible later stacking and post processing. Did this a time or two but just didn't find enough of an improvement to justify the extra time and effort.

I'm relatively new to astronomy / astro-photography having captured my first image in June of 2017. Early on in my journey and research of the hobby I came across https://www.nightskiesnetwork.com/ and the community of broadcaster and participants were a huge resource in helping me understand a lot of basic concepts and technical detail. I'm now a broadcaster and as part of the answer to question 3 when you have 5-30 folks watching your live stack and interacting via text and voice. I tend to show multiple objects each night and that limits the stack.

Forecast is calling for a clear night for me on Wednesday 1-16-19. If weather holds I should be broadcasting around 8:00 PM Eastern Time US.

https://www.flickr.com/gp/165305863@N04/001S79 This is my flickr with the latest live stacks and some live stacked images that were tweaked in Photoshop.

-Wikkett