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Jupiter w/GRS, Oval BA, Novel NTrZ White Spot [DSLR]

dslr Maksutov planet astrophotography
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#1 BQ Octantis

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Posted 24 August 2020 - 06:30 AM

G'day all,

 

Last night I was trying to get some detail on the GRS - Oval BA close encounter which culminates this week. I was about to wrap up the session when the novel white spot in the Northern Tropical Zone appeared on the LiveView screen. So I continued to capture for another hour and a half (going through one camera battery and half of another), for a total of 37 × 200 second captures:

 

get.jpg?insecure

 

These made for a nice animation; the seeing was good enough for a full-scale animated PNG:

 

Preview GIF @ 33%:

post-273658-0-55741300-1598260057.gif

Capture details / Animated PNG @ 100%

 

Enjoy!

 

Cheers,

 

BQ


Edited by BQ Octantis, 25 August 2020 - 12:53 AM.

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#2 Seven007

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Posted 24 August 2020 - 06:46 AM

That gif is really cool !

#3 LarsMalmgren

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Posted 24 August 2020 - 06:58 AM

Very very good animation.

You had a loong period of stable seeing bow.gif

 

Did you use the video function in your DSLR or did you take lots of single exposures ?

What telescope and camera did you use?



#4 BQ Octantis

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Posted 24 August 2020 - 08:34 AM

The seeing was good, but not entirely stable:

 

Screen Shot 2020-08-24 at 9.47.02 PM.png

 

This was the longest continuous session I've ever assembled. Over a typical 10-20 minute session, I can use a single set of convolution/wavelets to equalize the sharpness across the session. But over this two hour session, it took four different sets. The big difference here was that it went from meh to spectacular (as in 1-pixel deconvolution and no wavelets!) to very good and back to meh. So the trick was finding those transition points.

 

This is my setup:

 

post-273658-0-96655700-1556698565.jpg

 

I do 5× zoom LiveView capture over USB with AstroDSLR 1.3—version 1.3 peaks at 9.5 fps. I shoot 200 second intervals; the output is 54MB .mp4 files, each with ~1900 1024x680 frames, all of them key frames. After alignment (I use Lynkeos 2.10 for its speed), I downselect to the best ~1024 frames for stacking. The rest is just sharpening and histogram tricks.

 

BQ


Edited by BQ Octantis, 24 August 2020 - 06:00 PM.

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#5 Starman27

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Posted 24 August 2020 - 12:35 PM

Fine detail. Thanks for the capture information.



#6 ponz

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Posted 24 August 2020 - 02:44 PM

The seeing was good, but not entirely stable:

 

attachicon.gifScreen Shot 2020-08-24 at 9.47.02 PM.png

 

This was the longest continuous session I've ever assembled. Over a typical 10-20 minute session, I can use a single set of convolution/wavelets to equalize the sharpness across the session. But over this two hour session, it took four different sets. The big difference here was that it went from meh to spectacular (as in 1-pixel deconvolution and no wavelets!) to very good and back to meh. So the trick was finding those transition points.

 

This is my setup:

 

post-273658-0-96655700-1556698565.jpg

 

I do 5× zoom LiveView capture over USB with AstroDSLR 1.3—version 1.3 peaks at 9.5 fps. I shoot 200 second intervals; the output is 54MB .mp4 files, each with ~1900 1024x680 key frames. After alignment (I use Lynkeos 2.10 for its speed), I downselect to the best ~1024 frames for stacking. The rest is just sharpening and histogram tricks.

 

BQ

BQ,

 

How does the camera and T-thread attach to the eyepiece?confused1.gif confused1.gif  



#7 BQ Octantis

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Posted 24 August 2020 - 05:59 PM

Thanks to all for the feedback and likes!

 

Sorry for the confusion on the exploded view. The eyepiece goes into the "Mystery" adapter. The adapter is a T-threaded extension tube + eyepiece holder—it has a 1.25" flange on the interior for the eyepiece to contact, and if you look closely at the picture you can see the thumb screw that holds the eyepiece in place. "Mystery" is a now-defunct brand (these drop-shipped, straight-from-factory-in-China brands come and go quickly), but maybe in the image it's also literally a mystery! lol.gif

 

Here's the assembled setup (thumb screw visible, holding the eyepiece inside the adapter):

 

post-273658-0-73884900-1556697456.jpg

 

Hope that's a little clearer.

 

BQ


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#8 BQ Octantis

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Posted 25 August 2020 - 02:27 AM

Here was my best of the lot:

 

post-273658-0-12554600-1598340219.jpg


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#9 ponz

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Posted 25 August 2020 - 07:13 AM

Here was my best of the lot:

 

post-273658-0-12554600-1598340219.jpg

BQ'

 

This is one 200 second stack?

 

Ponz



#10 sunnyday

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Posted 25 August 2020 - 07:30 AM

very nice animation , superb details , thanks .



#11 BQ Octantis

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Posted 25 August 2020 - 08:29 AM

BQ'

 

This is one 200 second stack?

 

Ponz

Yep. Just 1024 frames, scaled to 65%.

 

Did you want the workflow? It's Mac-only; if you're a windows user it might still be useful…

 

BQ



#12 DubbelDerp

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Posted 25 August 2020 - 11:59 AM

Yep. Just 1024 frames, scaled to 65%.

 

Did you want the workflow? It's Mac-only; if you're a windows user it might still be useful…

 

BQ

I certainly would! I've tried using Lynkeos on my desktop, but haven't had much luck so I've been using AS!3 and Registax on my laptop. Not that I've had much better luck with that...



#13 ponz

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Posted 25 August 2020 - 12:00 PM

Yep. Just 1024 frames, scaled to 65%.

 

Did you want the workflow? It's Mac-only; if you're a windows user it might still be useful…

 

BQ

Absolutely.  I'm using Windows, but will see if I can adapt.

 

Cheers

John

aka - Ponz



#14 cdndob

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Posted 25 August 2020 - 04:00 PM

Sorry for the confusion on the exploded view. The eyepiece goes into the "Mystery" adapter. The adapter is a T-threaded extension tube + eyepiece holder—it has a 1.25" flange on the interior for the eyepiece to contact, and if you look closely at the picture you can see the thumb screw that holds the eyepiece in place. "Mystery" is a now-defunct brand (these drop-shipped, straight-from-factory-in-China brands come and go quickly), but maybe in the image it's also literally a mystery! lol.gif

 

Here's the assembled setup (thumb screw visible, holding the eyepiece inside the adapter):

The mystery adapter is a fairly common (I have one) projection camera adapter, Antares makes one. Some are adjustable, some are fixed in length.



#15 ponz

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Posted 25 August 2020 - 04:37 PM

I found one on Amazon

https://www.amazon.c...0?ie=UTF8&psc=1



#16 BQ Octantis

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Posted 25 August 2020 - 06:29 PM

I don't recommend extensible holders for eyepiece projection (I own two). For two reasons:

 

  1. Fully collapsed, they put the camera at the limit of the distance from the eyepiece. There is actually a limit above which you get strange ghosting in the image. The higher quality placement zone is closer to the eyepiece than you can get with the tube (at least for my 600D/T3i).
  2. The extension tube is prone to sag and shift. The two-screw model is certainly more secure than the single, but a rigid, all-screwed-together setup like the one I show will maintain its alignment in heavy winds. So you keep recording instead of having to halt and reacquire the planet.

 

The drop-shipped straight-from-factory-in-China ones are still easy to find on eBay. And even SVBony makes one that Amazon used to carry. They're still on eBay—just do a search for "T-thread extension tube" and the SVBony model will pop up among the knockoffs. Like this one:

 

https://www.ebay.com...OT/174198800093

 

BQ



#17 ponz

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Posted 25 August 2020 - 09:08 PM

I don't recommend extensible holders for eyepiece projection (I own two). For two reasons:

 

  1. Fully collapsed, they put the camera at the limit of the distance from the eyepiece. There is actually a limit above which you get strange ghosting in the image. The higher quality placement zone is closer to the eyepiece than you can get with the tube (at least for my 600D/T3i).
  2. The extension tube is prone to sag and shift. The two-screw model is certainly more secure than the single, but a rigid, all-screwed-together setup like the one I show will maintain its alignment in heavy winds. So you keep recording instead of having to halt and reacquire the planet.

 

The drop-shipped straight-from-factory-in-China ones are still easy to find on eBay. And even SVBony makes one that Amazon used to carry. They're still on eBay—just do a search for "T-thread extension tube" and the SVBony model will pop up among the knockoffs. Like this one:

 

https://www.ebay.com...OT/174198800093

 

BQ

BQ

 

I'm confused.  The link you provided doesn't show the entire assembly - does it?  I don't see where the eyepiece would go.

Plus - I have a Nikon and already have a T-adapter for it.

 

Ponz


Edited by ponz, 25 August 2020 - 09:12 PM.


#18 cdndob

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Posted 25 August 2020 - 10:29 PM

I don't recommend extensible holders for eyepiece projection (I own two). For two reasons:

 

https://www.ebay.com...OT/174198800093

 

On the link ponz provided there was a selection for a 1.25" Fixed camera adapter.



#19 cdndob

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Posted 25 August 2020 - 10:30 PM

BQ

 

I'm confused.  The link you provided doesn't show the entire assembly - does it?  I don't see where the eyepiece would go.

Plus - I have a Nikon and already have a T-adapter for it.

 

Ponz

Is goes inside the tube part with one screw to hold the eyepiece in a fixed position.



#20 BQ Octantis

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Posted 25 August 2020 - 10:46 PM

On the link ponz provided there was a selection for a 1.25" Fixed camera adapter.

Well no wonder I couldn't find the bloody thing! I knew SVBony made them, but they're lumped in with the other options. Ironically, I've tried all four (I returned the very last one).

 

BQ



#21 BQ Octantis

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Posted 26 August 2020 - 03:50 AM

I certainly would! I've tried using Lynkeos on my desktop, but haven't had much luck so I've been using AS!3 and Registax on my laptop. Not that I've had much better luck with that...

Absolutely.  I'm using Windows, but will see if I can adapt.

Ok, just remember you guys agreed to it. Just realize that every planetary imager will tell you everything in the workflow is wrong from top to bottom. So be it. I like the images it produces.

 

The flow starts with good seeing and good altitude on the planet. If it's below 30˚, it's going to be quite difficult to get good results. Ironically, zenith isn't a panacea either—the sweet spot seems to be between 40 and 60˚. I can only assume this is because of the rapid volume of air increase as you decrease altitude from 40˚ to the horizon and the fast increase in tangential air mass velocity as you increase from 60˚ to zenith. Chromatic dispersion by the atmosphere is also a problem below 40˚. The jet stream velocity is a big factor, too—I rarely even set up for planetary if it's above 50 m/s. And I've started setting up well away from my house—the metal roof gives off a tall plume that takes hours to settle after sunset.

 

I already showed you my setup. With the 12.5mm eyepiece, I estimate I'm shooting at ~f/58. Yes, I meant to write f/58. I actually have no idea what the focal ratio is—I just try to get as many of the 1024×680 pixels of the 5× zoom across Jupiter. And don't go quoting Nyquist on me—we had an intense debate on resolution vs. detection over in the planetary forum and concluded that an aperture can easily detect features to at least 10× Rayleigh—so there is your reference spatial information rate! I'm sampling somewhere around 4.4× Rayleigh, so I'm nowhere even close to the Nyquist criterion for that. And at Ts = 1/30sec, Jupiter has the SNR for f/58. Don't believe it? Look at the image. Truth be told, I shim the eyepiece with rubber bands, like this:

 

post-273658-0-83980600-1561769852.jpg

 

But this is just to make Jupiter a little smaller so I can keep it on the sensor during poor seeing and gusty ground winds that conspire to drive it off the sensor crop—a frequent occurrence in the outback.

 

The capture and processing workflow is all simple after that:

 

gallery_273658_12412_28691.jpg

 

I included the version numbers for the software I use. AstroDSLR and Lynkeos are consciously older versions, simply for their speed (their subsequent upgrades were catastrophic).

 

Capture in AstroDSLR is fairly straightforward:

 

(Click for full size.)

gallery_273658_12412_280636.jpg

 

Note that I'm using AWB vice daylight. This is because we're getting an 8-bit JPEG off the LiveView and not a 14-bit RAW. When I capture with Daylight, the blues and reds are quite compressed in the stack. Planetary targets are in full sun, and AWB makes better (or at least more complete) use of all three histograms. I use the ISO12800 setting because it gives me the greatest control on the actual gain of the sensor. Yes, we're actually only controlling ISO—the capture settings are simulated because the actual Ts (at least for LiveView off the 600D/T3i) is fixed at 1/30sec. For the optimal gain, I just adjust the Ts setting until the histogram max is just under 50,000. For this capture, Ts was 1/200sec. By simple math, this was a gain of ~ISO1920; with the eyepiece unshimmed, I'm usually at 1/160sec or ISO2400. Make sure you click the Zoom button to get 5× zoom. And click the preview downscaling button—with the upscaling button, capture peaks at ~8 fps; downscaling takes it up to ~9.5. With all that set, just do a 200sec recording. Since I display my time with seconds on my menu bar, I just add 3 minutes and 20 seconds from after I clicked the record button and clicked "Save".

 

Once you've got the .mp4 saved, fire up Lynkeos 2.10. Drop the .mp4 on the window, and it will parse out all the frames. A curious note about Lynkeos: it will only load key frames. AstroDSLR seems to store every frame as a key frame, but the in-camera video does not. So if I want to use all the frames from an in-camera video at 30 fps, I actually have to rip the .mov into frames with a ripper. This approach is much simpler, and I get much better results. So here's the .mp4 loaded and parsed:

 

gallery_273658_12412_67912.jpg

 

For alignment with Lynkeos, I find the alignment frame size needs to be about 50% bigger than the target's largest extent. It can be bigger—up to 300 pixels for a 5-pixel star—but it seems to be most accurate at 50%. In this case, that was 700 pixels. If your Jupiter drifted outside of that, start with a bigger box for a first pass, and then do it again with a 150% box.

 

A note about speed. If you want to watch the images update during the alignment, it can be mesmerizing to watch them all fly by. But if you want speed—as in the full stack aligned in seconds, turn this feature off in the preferences:

 

gallery_273658_12412_55493.jpg

 

Once aligned, we move on to downselection based on quality.

 

gallery_273658_12412_29548.jpg

 

I haven't figured out where the default settings come from, but the low setting of 0.08 doesn't correspond to anything I've ever shot. Just click the preview check box and increment the low frequency down until you find where you get the most interpixel details in the Fourier Transform view of the image. For mine, this was at 0.01. Then put the sampling box on the greatest extent you can put on the disk—in this case, this was 300 pixels. Note that if you scroll down through the images, the Fourier image is out of alignment. This is because Lynkeos does the Fourier Transform on the original frame, not the alignment. So just make sure you're using your "Reference" alignment image (typically the first one, unless you selected a different one during alignment). Unclick the "Preview" check box and click "Analyze". Seconds later, you'll have useful quality metrics:

 

gallery_273658_12412_49286.jpg

 

Once you've got your metrics, you just find the cutoff value that gives you ~1024 frames. Another amusing oddity about Lynkeos: it can't stack 1024 frames. It will tell you it can, but when you get to stacking, it just won't finish. Like a soft divide by zero somewhere. So I target the value that gives me the lowest value above 1024 frames, which in this case gave me 1030. I promise you, 6 images won't make a difference in the stack. You can use the slider, but I just do this manually; I increment by 10, then by 5, then by 1, then by 0.1, and then by 0.01 to find the value. Once you've downselected, you're ready to stack:

 

gallery_273658_12412_99529.jpg

 

Stacking is as easy as it sounds. But if you have several images that you want to batch process (like I did the ones in the first post), you probably want to use a common size for all of them. In this case, 720×600 framed it nicely.

 

If you want to save your work, now is the time to do so. Once you stack the image, Lynkeos will include the stacked frame in the project file if you save it. Oddly enough, you can't actually get to the stacked image—indeed, the stack is lost the moment you go to another pane, so you then need to restack. So if you want to save several MBs per space for the settings file this is the point to save it. (It makes a much bigger difference for RAW stacks of the deep sky.)

 

Click Stack, and seconds later you'll have a stacked image:

 

gallery_273658_12412_92282.jpg

 

Save this as a 16-bit TIFF, and we're ready for the third step in the workflow…

 

Assuming there's still interest after all thatsmile.gif

 

BQ


Edited by BQ Octantis, 26 August 2020 - 04:13 AM.

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#22 ponz

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Posted 26 August 2020 - 08:10 AM

Ok, just remember you guys agreed to it. Just realize that every planetary imager will tell you everything in the workflow is wrong from top to bottom. So be it. I like the images it produces.

 

The flow starts with good seeing and good altitude on the planet. If it's below 30˚, it's going to be quite difficult to get good results. Ironically, zenith isn't a panacea either—the sweet spot seems to be between 40 and 60˚. I can only assume this is because of the rapid volume of air increase as you decrease altitude from 40˚ to the horizon and the fast increase in tangential air mass velocity as you increase from 60˚ to zenith. Chromatic dispersion by the atmosphere is also a problem below 40˚. The jet stream velocity is a big factor, too—I rarely even set up for planetary if it's above 50 m/s. And I've started setting up well away from my house—the metal roof gives off a tall plume that takes hours to settle after sunset.

 

I already showed you my setup. With the 12.5mm eyepiece, I estimate I'm shooting at ~f/58. Yes, I meant to write f/58. I actually have no idea what the focal ratio is—I just try to get as many of the 1024×680 pixels of the 5× zoom across Jupiter. And don't go quoting Nyquist on me—we had an intense debate on resolution vs. detection over in the planetary forum and concluded that an aperture can easily detect features to at least 10× Rayleigh—so there is your reference spatial information rate! I'm sampling somewhere around 4.4× Rayleigh, so I'm nowhere even close to the Nyquist criterion for that. And at Ts = 1/30sec, Jupiter has the SNR for f/58. Don't believe it? Look at the image. Truth be told, I shim the eyepiece with rubber bands, like this:

 

post-273658-0-83980600-1561769852.jpg

 

But this is just to make Jupiter a little smaller so I can keep it on the sensor during poor seeing and gusty ground winds that conspire to drive it off the sensor crop—a frequent occurrence in the outback.

 

The capture and processing workflow is all simple after that:

 

gallery_273658_12412_28691.jpg

 

I included the version numbers for the software I use. AstroDSLR and Lynkeos are consciously older versions, simply for their speed (their subsequent upgrades were catastrophic).

 

Capture in AstroDSLR is fairly straightforward:

 

(Click for full size.)

gallery_273658_12412_280636.jpg

 

Note that I'm using AWB vice daylight. This is because we're getting an 8-bit JPEG off the LiveView and not a 14-bit RAW. When I capture with Daylight, the blues and reds are quite compressed in the stack. Planetary targets are in full sun, and AWB makes better (or at least more complete) use of all three histograms. I use the ISO12800 setting because it gives me the greatest control on the actual gain of the sensor. Yes, we're actually only controlling ISO—the capture settings are simulated because the actual Ts (at least for LiveView off the 600D/T3i) is fixed at 1/30sec. For the optimal gain, I just adjust the Ts setting until the histogram max is just under 50,000. For this capture, Ts was 1/200sec. By simple math, this was a gain of ~ISO1920; with the eyepiece unshimmed, I'm usually at 1/160sec or ISO2400. Make sure you click the Zoom button to get 5× zoom. And click the preview downscaling button—with the upscaling button, capture peaks at ~8 fps; downscaling takes it up to ~9.5. With all that set, just do a 200sec recording. Since I display my time with seconds on my menu bar, I just add 3 minutes and 20 seconds from after I clicked the record button and clicked "Save".

 

Once you've got the .mp4 saved, fire up Lynkeos 2.10. Drop the .mp4 on the window, and it will parse out all the frames. A curious note about Lynkeos: it will only load key frames. AstroDSLR seems to store every frame as a key frame, but the in-camera video does not. So if I want to use all the frames from an in-camera video at 30 fps, I actually have to rip the .mov into frames with a ripper. This approach is much simpler, and I get much better results. So here's the .mp4 loaded and parsed:

 

gallery_273658_12412_67912.jpg

 

For alignment with Lynkeos, I find the alignment frame size needs to be about 50% bigger than the target's largest extent. It can be bigger—up to 300 pixels for a 5-pixel star—but it seems to be most accurate at 50%. In this case, that was 700 pixels. If your Jupiter drifted outside of that, start with a bigger box for a first pass, and then do it again with a 150% box.

 

A note about speed. If you want to watch the images update during the alignment, it can be mesmerizing to watch them all fly by. But if you want speed—as in the full stack aligned in seconds, turn this feature off in the preferences:

 

gallery_273658_12412_55493.jpg

 

Once aligned, we move on to downselection based on quality.

 

gallery_273658_12412_29548.jpg

 

I haven't figured out where the default settings come from, but the low setting of 0.08 doesn't correspond to anything I've ever shot. Just click the preview check box and increment the low frequency down until you find where you get the most interpixel details in the Fourier Transform view of the image. For mine, this was at 0.01. Then put the sampling box on the greatest extent you can put on the disk—in this case, this was 300 pixels. Note that if you scroll down through the images, the Fourier image is out of alignment. This is because Lynkeos does the Fourier Transform on the original frame, not the alignment. So just make sure you're using your "Reference" alignment image (typically the first one, unless you selected a different one during alignment). Unclick the "Preview" check box and click "Analyze". Seconds later, you'll have useful quality metrics:

 

gallery_273658_12412_49286.jpg

 

Once you've got your metrics, you just find the cutoff value that gives you ~1024 frames. Another amusing oddity about Lynkeos: it can't stack 1024 frames. It will tell you it can, but when you get to stacking, it just won't finish. Like a soft divide by zero somewhere. So I target the value that gives me the lowest value above 1024 frames, which in this case gave me 1030. I promise you, 6 images won't make a difference in the stack. You can use the slider, but I just do this manually; I increment by 10, then by 5, then by 1, then by 0.1, and then by 0.01 to find the value. Once you've downselected, you're ready to stack:

 

gallery_273658_12412_99529.jpg

 

Stacking is as easy as it sounds. But if you have several images that you want to batch process (like I did the ones in the first post), you probably want to use a common size for all of them. In this case, 720×600 framed it nicely.

 

If you want to save your work, now is the time to do so. Once you stack the image, Lynkeos will include the stacked frame in the project file if you save it. Oddly enough, you can't actually get to the stacked image—indeed, the stack is lost the moment you go to another pane, so you then need to restack. So if you want to save several MBs per space for the settings file this is the point to save it. (It makes a much bigger difference for RAW stacks of the deep sky.)

 

Click Stack, and seconds later you'll have a stacked image:

 

gallery_273658_12412_92282.jpg

 

Save this as a 16-bit TIFF, and we're ready for the third step in the workflow…

 

Assuming there's still interest after all thatsmile.gif

 

BQ

GULP



#23 BQ Octantis

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Posted 26 August 2020 - 08:35 AM

GULP

lol.gif  I just meant you guys agreed for me to post it!

 

BQ


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#24 ponz

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Posted 26 August 2020 - 08:47 AM

lol.gif  I just meant you guys agreed for me to post it!

 

BQ

Daunting - simply daunting!

 

Ponz



#25 DubbelDerp

DubbelDerp

    Apollo

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  • Posts: 1,496
  • Joined: 14 Sep 2018
  • Loc: Upper Peninsula of Michigan

Posted 26 August 2020 - 10:19 AM

Interesting! I captured some data on Jupiter a few weeks ago that I used for my ham-handed attempt at stacking in AS!3, but I'll have to run through your workflow with Lynkeos. Your single frame is much cleaner than any of mine, but Jupiter is so low on the horizon here that I don't think there's any helping that. I did use a 2x Barlow with my 8" SCT to get to f/20 and shot at 5X live view through BYEOS, but I'll have to pick up one of those eyepiece projection adapters to compare. I'm pretty sure my older Meade Plossls are of better quality than the cheap barlow I bought...

 

Thanks for taking the time to write it up in so much detail!




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