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

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

Post by carlwagle » Thu Aug 01, 2019 4:20 am

I use a Celestron SKYPRODIGY 130 Computerized Telescope. Focal length of 650mm and a focal ratio of 5. It has been an inexpensive and satisfactory way for me to get introduced to astrophotography.
My camera is a ZWO ASI 178MC.

I did a lot of reading on the forum but can't find any problem reported like I'm about to make.

My problem is after doing everything right to get a good image of M27 (looking like a wispy green bow tie) in my work screen after realizing I'm not going to see it at all with less than a 25 second exposure using a gain of 495,, then getting Live Tracking started (with just a few out of say 30 dropped) when I press the save button then go take a look at the Fits Lib. picture I see no trace of the M27 image,, not even a slight smudge of it, just a clean black void surrounded by very well focused stars.
While I'm tracking I do see the image staying in the small screen above the histogram, but the image does not improve (get brighter) as frames are added and stacked. When I choose to see the individual frames as they are made, I can, and the wispy image is there, and you can tell when each new image is made by very slight motions or drifting of the stars make by imperfect tracking. But the end results (after at least 20 tries, over two nights) shows no M27, just its field of surrounding stars.
I can take single PNG File pictures and see the bow tie very well.
At first I thought my dark frame was interfering with the saved image since it was based on such a different camera settings so I made a new one. Reviewed it before using it. Found a lot of noise on it as expected with 31 sec. exposures, gain of 500, camera temp I think at 26C.. But the new Dark Frame did not change a thing.
There are 3 other keys you can press to make a save, one of them is SAVE AS SEEN. All except the SAVE AS A 32 BIT (it is a washed out white screen with a bunch of close dots) show the bow tie.

I will quickly follow up this posting by sending out a camera settings history for one of the failed Fits Lib. stackings in hopes someone might spot my problem. Or I've perhaps already described it enough for some one to guide me to understanding how to overcome it. Thanks, Carl Wagle

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

Post by carlwagle » Thu Aug 01, 2019 4:28 am

Here is one of my camera settings.
The only thing I can tink of That I might have tried,but failed to think of, was trying to stack not applying a Dark Frame. But I doubt that would be my problem.

[ZWO ASI178MC]
Debayer Preview=On
Pan=0
Tilt=0
Output Format=PNG files (*.png)
Binning=1
Capture Area=3096x2080
Colour Space=RAW16
Temperature=27
Hardware Binning=Off
High Speed Mode=Off
Turbo USB=40
Flip=None
Frame Rate Limit=120 fps
Gain=499
Exposure=32.702431
Timestamp Frames=Off
White Bal (B)=49
White Bal (R)=50
Brightness=64
Auto Exp Max Gain=130
Auto Exp Max Exp M S=13631
Auto Exp Target Brightness=106
Mono Bin=Off
Banding Threshold=35
Banding Suppression=0
Apply Flat=None
Subtract Dark=C:\Users\CHWag\Desktop\SharpCap Captures\darks\ZWO ASI178MC\RAW16@3096x2080\32.7s\gain_499\dark_10_frames_27.5C_2019-07-31T06_15_05.png
#Black Point
Display Black Point=0
#MidTone Point
Display MidTone Point=0.774725274725275
#White Point
Display White Point=1
TimeStamp=2019-07-31T06:43:54.7771070Z
SharpCapVersion=3.2.5986.0
TotalExposure(s)=1308.09724
StackedFrames=40


Thanks for any help, Carl

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

Post by BlackWikkett » Thu Aug 01, 2019 2:25 pm

carlwagle wrote:
Thu Aug 01, 2019 4:28 am

Output Format=PNG files (*.png)
The camera settings file you provided shows output format .png I'm not sure if Fits Liberator can open this file type. If you're opening single frames you may need to apply a significant stretch to see faint objects in Fits Liberator. Open in Fits Liberator then from there save as a .tiff and open the image in an other app like Photoshop or Gimp and apply a stretch.

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

Post by admin » Fri Aug 02, 2019 8:06 pm

Hi,

In the camera settings you post it looks like you've moved the mid-grey point for the display stretch upwards, which has the effect of making the faint detail like nebulousity or galaxies an image less visible. I'd suggest putting this back to the default of having the mid-grey point in the middle, or even moving it to the left which will enhance the brightness of the faint stuff. I'm talking about the adjustments here in the mini histogram on the right-hand side rather than those in the life stacking panel.

Cheers, Robin

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

Post by carlwagle » Sat Aug 03, 2019 4:45 am

Thank you Robin for your suggestion. I will take it into the Field on the next clear night and let you know what happens. Please keep an eye open for my reply as it might be MANY nights away. I have noticed in the past when stacking on M51 (like ten attempts) I was missing so much of it that I was not sure I had it centered in the scope, so yes I could loose out on faint things.

First I would like to say that I entered into this huge challenge for a 78 year old "Newbie" with the understanding that a fair job of Astrophotography (not like Nassa promotes) could be accomplished by most average people, like me if they chose SharpCap as their guide into this difficult but rewarding endeavor.
I early on have had the impression that I did not need to subscribe to GIMP, PHOTOSHOP. AUTOSTAKERT, or even NEBULOSITY. All these are often mentioned in the Forum by other people than yourself as if they are useful if not in fact needed. For a beginner like me I think it best for me to understand First, Sharpcap alone. And believe me,, that's a Handful!. Also I would like to see some Gallery pictures that label themselves RENDERED ONLY BY SHARPCAP somewhere within,, well that's for "Newbies" like me.

Robin,,, in your reply are you discussing adjustments to the histogram that is illustrated in the present SharpCap Users Manual? There it is found by scrolling down to CAMERA CONTRO PANEL. This histogram is discussed under the descriptive line MINI HISTOGRAM AND DISPLAY STRETCH. Are you writing that if I moved the center line to the left of the default setting that should enhance the the image of the 'fuzzy bow tie'?
I see in my camera settings where you read Display Midtone Point .774 ect. ect. Does that number get bigger or smaller as I move the center line to the left?
If I am wrong about the means to make this grey tone adjustment (I feel 80% sure that I'm right) could you please elaborate on your directions?

Thanks again for all the hard work you have put into SharpCap. Carl Wagle

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

Post by admin » Sun Aug 04, 2019 1:04 pm

Hi Carl,

Yes, when you move the midpoint line to the left in the display histogram the image on screen will brighten – particularly the darker areas of the image will be brightened making it easier to see deep sky targets. This change will give a lower value for the midpoint saved in the settings file. The default value of 0.5 for the midpoint would not brighten or dim the image. Values less than 0.5 would tend brighten the faint parts of the image while values greater than 0.5 or 10 to dim the faint parts of the image.

Note that adjusting the sliders in the right-hand panel only affects the image as seen on screen in SharpCap. It does not affect the brightness of the image save to file (unless you save using the little save icon that is in the mini histogram area – that does save with all adjustments applied so you should see an image in your saved file that looks exactly like the one you see on screen in SharpCap).

Hope this helps, Robin

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

Post by carlwagle » Mon Aug 05, 2019 12:52 am

Thanks Robin, I'm going to find that save icon you mentioned right now, because I think that will be needed.
I'm also going to re-read the instruction manual front to back. I'm presuming the one I can get off of this HELP SITE is very up to date and might cover some things last years version, which I "saved") might lack.

I'm going to use the SharpCap practice camera (deep sky) a lot more too. Carl

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

Post by carlwagle » Thu Aug 08, 2019 1:23 am

Brian,, on my last time out I did find and move that center line to the left. I took two stacked sequences from two different positions when moving left. There is still no image at all (except for a good star field) to be seen in the stacked Fits Lib. picture. But a better single picture image does show up when the save as seen button is pressed. I think that same button can be found twice, once beneath the small histogram that always stays on,, and again when live stacking is chosen and HISTOGRAM button (I think second from the left)is punched in the top line of selections which brings in a much larger histogram. Both put a single picture in the same file.

One big difference in what I'm now doing from what I use to do in the past is I'm using such large exposures (like 31 seconds) when 12 seconds got the job done. Also gains of 515, Max. when 350 use to be enough. I have used 25 seconds and gain of 495 but that Stepping Back does not change the bad outcome.

Choosing not to use a Dark Frame does not help solve the problem either.

A very careful re-read of the manual and taking notes might be what it takes but I have my doubts.

Do you need anymore info from me or have any suggestions as to what I can try? Carl

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

Post by nexusjeep » Thu Aug 08, 2019 7:37 am

Are you saving a fits or a PNG stacked image as the original header was for a PNG image and I think FITS Lib only loads fits files so if the Stacked image is indeed a PNG you must be loading one of the individual subs if viewing in FITS Lib. IF this is the case then these would be unadjusted and as such I would solely expect to see the brighter stars and nothing else as the image needs to be stretched to see the nebulosity details /dimmer objects. This would also explain why you see it in Sharpcap in the live stack view if you have stretched or used auto stretch in the histogram tab.

Do you have a PNG file in the same folder with the FITS files if so open this in window picture viewer or similar to see what is there if this has been saved unadjusted you will again only see the stars unless you stretch the data.

As an example this is a single fits for the soul nebula unstretched you can only see the brighter stars. These are 120s x 200 gain on my ASI1600MM pro
Fits unstretched.png
Fits unstretched.png (78.15 KiB) Viewed 418 times
This is the same shot with a rapid and rough stretch applied.
Fits stretched.png
Fits stretched.png (961.43 KiB) Viewed 418 times
Cheers
Nick

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

Post by carlwagle » Sat Aug 10, 2019 5:02 am

Nick
You have done a great job with the 2 pictures showing exactly what I reported. Your first picture shows the expected stars with no nebulosity and that is how my stacked Fits Lib. picture turns out. The second (very rich in details) shows what I would expect a stack of ten or so frames should have exhibited with my camera settings that I posted.

From what I wrote and the camera settings I sent in, can you see what I did wrong or perhaps offer some things to try that are understandable within the SharpCap Manual? I'm not familiar with any other image/capture/processing technique.

A lot of your questions I'm not sure how to begin to answer. I think you may have experience that goes way back to Eastman Kodac 35mm film days with telescopes and you are very familiar capturing a series of frames and transferring them to other files, perhaps between computers. I'm not. The most camera I ever owned was a metal box 'pin hole' camera that shot a film known as 120 (back in the 1950's). I've never owned and don't intend to buy a cell phone. My 51 year old son helped me buy the Right computer and has helped me quite a bit to reach this level of ability and considering all that,, I'm pretty happy with what I've achieved with SharpCap. My son might be able to help me answer your questions without me guessing at them in a couple of weeks.

I'm re-reading the SC manual, very carefully, hoping I can solve this problem. But this is a "Make or Break situation. From what I've seen recently I'm not going to be able to get a stacked picture of the Andromeda Galaxie after almost a year of preparation.

Here is an appropriate question: what proof is there that the questionable resulting imageless so-reported staked image the Fits Lib. provides was indeed stacked at all?

One thing that would begin to help me is an explanation of the words stretch and stretching. Every time I see them used in the Forum I have no clear idea of what process they are describing. I'm not sure if the SC manual introduces those words in such a way a new user fully understands them. How do the words MAGNIFY and STRETCH differ when it comes to astrophotography. To me it seems like our gain control is a form of stretching. Carl

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