I can't find a stacked image of M27 in my Fits Lib. File

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carlwagle
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Re: I can't find a stacked image of M27 in my Fits Lib. File

Post by carlwagle » Fri Aug 16, 2019 6:16 pm

Thanks for all this Dave. Now I'm just as optimistic as I was when I first decided to use SC. I will study, take my time, be prepared to get some knowledge outside of SC,, and whip this problem! Carl

carlwagle
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Re: I can't find a stacked image of M27 in my Fits Lib. File

Post by carlwagle » Tue Sep 10, 2019 3:52 am

Dave, today you answered a post I made last night concerning my asking for the default settings for Banding Threshold and Suppression. You suggested that I start a new thread. But I think continuing this one is more to the point as I'm still trying to figure out what my original problem is. The post you recently read was an effort to find something that is unknown by me that just might solve the problems.

It is quite certain to me that I have two perhaps unrelated problems. One is no nebulosity is being stacked. The second one is an error in the product of stacking. I think I described both adequately early on. I would like to add here more info on that stacking problem. When ever I review a Fitz Liberator or the picture taken by the lowest button in the column identified as SAVE EXACTLY AS SEEN both have in their 'title' words to the effect that this is a stacked picture. But neither are. I do not see in the final pictures dim stars becoming brighter due to stacking and I would expect to see more of the Andromeda M-31 after 100 "stacked" frames,, each having 31 second exposures than I captured a couple of nights ago. That would be over 50 minutes of total exposer. The final picture is nothing more than the first picture that is put onto the work screen in both capture modes.

Let us ignore the nebulosity problem and concentrate on this stacking problem. What test would you like me to run in the field to prove to you that it exists? What supporting pictures and data would you like too?

Related to what I just typed and may be something like what you would want: on my last outing I began a stacking process (I believe) on M-45. I saved this. It might have been on just a wad of stars that I wanted to prove my case on, that is there is no stacking going on when every normal and expected indication tells me that it is. Since the exposure time was so long I was able to press the SAVE EXACTLY AS SEEN for the first image and did the same for 10 images in a row. What was recorded was 10 separate unique pictures but there was no stacking as a final result.

Yes M-45 would be a good target over time as it is coming onto 'the scean' whereas M27 is leaving soon.

I just tried out that stetch button you mentioned while using the SC provided Deep Sky Camera. It made the image look very over exposed and I don't see how that could be useful. Carl

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turfpit
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Re: I can't find a stacked image of M27 in my Fits Lib. File

Post by turfpit » Tue Sep 10, 2019 7:04 am

Carl
Let us ignore the nebulosity problem and concentrate on this stacking problem
Agreed. If stacking is not working then there will be no nebulosity.
What test would you like me to run in the field to prove to you that it exists? What supporting pictures and data would you like too?
I will create a new thread maybe called 'Howto - Basic Live Stack Troubleshooting' which will give examples of the information required to help forum members to assist the poster. This thread will include examples of material to post including screen shots, logs and camera settings. It will take me a few days to produce - depends on the weather. If I can get this right (and that may not happen at first attempt) then others coming along with basic Live Stack problems will have a useful resource they can be directed to. Over time, I am sure the the resource will be improved, as other forum members who are more experienced with Live Stack than me (such as BlackWikkett - sorry Chris) will hopefully contribute to add to and refine the information.
Related to what I just typed and may be something like what you would want: on my last outing I began a stacking process (I believe) on M-45. I saved this. It might have been on just a wad of stars that I wanted to prove my case on, that is there is no stacking going on when every normal and expected indication tells me that it is. Since the exposure time was so long I was able to press the SAVE EXACTLY AS SEEN for the first image and did the same for 10 images in a row. What was recorded was 10 separate unique pictures but there was no stacking as a final result.
This is a good example of information that is no help at all. Remember - a picture is worth a thousand words.
I just tried out that stetch button you mentioned while using the SC provided Deep Sky Camera. It made the image look very over exposed and I don't see how that could be useful.
That is the idea of the Autostretch button. It brightens the image (it may look horrible) in order to assist the imager see if the object is actually there. The Autostretch button does not affect the data, only how the data is displayed.

The Deep Sky Camera could be used as a training tool to enable an imager to practice indoors - this will remove reliance on the weather or darkness. I will have a think about that and experiment.

I will post back here when I have produced some notes (which will be in another new post so as to be easily identified by others).

Can I suggest you find out how to capture screens using the PrintScreen key on your keyboard and the Windows Snipping Tool. Also find out how to get those pictures and a camera settings file into a forum post. These techniques will be needed for posting back relevant information.

Dave

carlwagle
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Re: I can't find a stacked image of M27 in my Fits Lib. File

Post by carlwagle » Tue Sep 10, 2019 6:19 pm

Dave, Im confused by what you write here: "This is a good example of information that is no help at all. Remember - a picture is worth a thousand words." because I had just said that I could provide 10 (or any part of that number) pictures to prove that no tracking had occurred when I had every reason to think it had. I think each picture has its camera settings page available too.

I think your writing a tutorial (if that is what you meant) would be a good idea. Do I understand correctly that when you have finished this tutorial you are going to post it here as a reply and as a new thread some place else at the same time?
But I wish you would stay with me and get this problem solved. I have asked you what test would you like for me to make and what supporting data would you want me to send you. I will try to learn to do screen shots very soon. I could do them several months ago but now I have forgot how to do them with no more exercise of that skill being called for over that period of time.

Would that stretch button we last talked about have momentarily revealed the 'arms or bands' of m31 or m51?

I think it would be beneficial for the operator of SC to be able to get a picture of the results of using ZOOM when the the button SAVE EXACTLY AS SEEN is pressed. As things stand right now this can't be done, the zoom is ignored, you get a 'standard' picture.
One thing I proved on my last outing was that there is a limit to how much exposure I can use and get good successive tracking with the Celestron Go To mount. 60 seconds allows for so much distortion in the stars recorded shapes that tracking fails. 31 seconds works with sometimes one out of roughly four frames being rejected. From now on, 29 seconds is going to be my max to operate with. Carl

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turfpit
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Re: I can't find a stacked image of M27 in my Fits Lib. File

Post by turfpit » Tue Sep 10, 2019 8:16 pm

Carl

I will write a tutorial and put it in one place (probably in the Tutorials sub forum). That way it has a chance of being found by many people.
I will also post a link to it in this thread.
I will try to learn to do screen shots very soon
Good, this is important to be able to capture and post pictures of what exactly is happening.
Would that stretch button we last talked about have momentarily revealed the 'arms or bands' of m31 or m51
yes - if the stacking was working correctly.

For your equipment, 30s would be a realistic exposure.

Dave

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Re: I can't find a stacked image of M27 in my Fits Lib. File

Post by carlwagle » Wed Sep 11, 2019 4:13 am

Dave, about this:
"Would that stretch button we last talked about have momentarily revealed the 'arms or bands' of m31 or m51? "
What you say may be a diagnostic aide in determining wether proper stacking is occurring or not so I look forward to using it when the moon starts to come up after about 3;00am. soon. It would be helpful if you could come up with some other similar diagnostic aides. Over and Out, Car

carlwagle
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Re: I can't find a stacked image of M27 in my Fits Lib. File

Post by carlwagle » Sun Nov 24, 2019 6:36 pm

Dave, Ive been looking forward to that Tutorial on stacking you mentioned that you would post (I guess) on this forum about Stacking but have I missed it somehow?
I recently converted my GoTo mount to an equatorial mount by turning its normal vertical axis over on its side enough to point at Polaris and doing what ever is needed to the tri pod to make this possible. By using the sidereal time drive provided by Celestron (it's about 90% right) I was able to capture much more of the nebulosity (or glowing field) of the Orion Nebula. The single picture that I can take by using SAVE AS EXACTLY SEEN looks as good as published in astronomy books back in 1988. There are now more pictures accepted when using LIVE STACK with shorter exposure and less gain,,,, all this would seem to be an improvement for STACKING. However, I still doubt I'm getting any stacked results.

One question I have here today::: Am I right when I say the Fits Liberator picture should show at least (if not more) as much of a glow field (nebulosity?) as the single PNG picture does?? I call that glow, data. If I can't see it before processing I assume none is there. Carl

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turfpit
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Re: I can't find a stacked image of M27 in my Fits Lib. File

Post by turfpit » Mon Nov 25, 2019 7:52 pm

Sorry Carl, not done yet. The weather has been poor for the last couple of months and at the moment my mount is away for a refurb/service/tune. It will get done - I will probably use M42 now.

For M42, with a correctly exposed histogram, there would be very little visible on the screen during a capture. The detail has to be brought out by stretching the image. The stretch can be applied by using the Display Histogram Stretch, which affects only the display but does not alter the data. The result of the stretch could be captured by selecting Save as Seen or processing the result with a program such as GIMP (using Curves).

This is a 4s capture of M42 loaded into the test camera. M42 is dead centre but not visible. I know the capture is good because the log histogram is the classic shape for a deep sky object - slight gap at the left hand side, rising sharply, then tailing off gradually.

M42-4s-unstretched.JPG
M42-4s-unstretched.JPG (88.66 KiB) Viewed 300 times


By applying the Display Histogram Stretch, the nebula can be seen. This does not alter the captured data. Because it is a single frame, the background is noisy. By stacking lots of frames, the background noise will be reduced resulting in a smoother image.

M42-4s-stretched.JPG
M42-4s-stretched.JPG (179.04 KiB) Viewed 300 times


Here is the same frame loaded into FITS Liberator. Again I know the object is there because of the shape of the histogram with further verification being the Min is greater than 0 and the Max is less than 65535

FITS-Liberator.JPG
FITS-Liberator.JPG (97.67 KiB) Viewed 300 times


These are the capture settings for the frame.

FITS-Liberator-capture-settings.JPG
FITS-Liberator-capture-settings.JPG (76.54 KiB) Viewed 300 times


This is the result of stacking 100x4s exposures.

M42-4s-100-stack.JPG
M42-4s-100-stack.JPG (55.44 KiB) Viewed 299 times


This is the result of stacking 60x60s exposures.

M42-60s-60-stack.JPG
M42-60s-60-stack.JPG (72.8 KiB) Viewed 297 times




Try posting back some of your capture screens, this would make it easier to help you.

Dave

carlwagle
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Re: I can't find a stacked image of M27 in my Fits Lib. File

Post by carlwagle » Wed Nov 27, 2019 3:06 am

Dave, in closing I will try send you a picture of M42 that I took with my converted (to equatorial) GoTo mount (a Celestron SKYprodogy). It is not a staked picture. It was taken while stacking by selecting TAKE EXACTLY AS SEEN, while using Live Stacking, which gives a very nice color picture.

On thing you have made clear is that the, for instance a 273 staked frames one, is going to be not showing much detail like nebulosity in a FITS picture as compared to something like I'm showing you. I can see a lot on a Fits shot of M42 as compared to M27, which is totally nothing where it is suppose to be. I think you have said lately that SC subtracts something like trash in the FITS Picture and I have seen something like that in many of my dense star cluster captures. I see that I lack the really fine stars that better tracking rigs can produce. My SKYprodigy produces just enough uneven (oblong?) star shapes that perhaps the fine "dusty" ones are thrown out,, and the same thing could happen with pale nebulosity.

I'm buying a new Orion Astroview 120st (4.7in refractor)on an equatorial mount with single axis motor drive for $599 delivered. I think this will solve my nebulosity problems.

Let me ask you one question for the moment: while using SC Live Stacking, is there someplace I can find a picture that shows the summation of the staking up till that point in time,,, while the stacking sequence continues? As I understand it right now the answer is no,,, the final staked picture is the FITS Lib. but I'm not sure of what I just said.

I tried and could not send that picture, by using the ATTACHMENT button below and the the Add Files. Too much MB involved. Carl

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