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

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

Post by galljj » Mon Aug 12, 2019 12:05 am

Carl You might want to take a look at the unofficial sharpcap quickstart guide over on cloudy nights. See https://www.cloudynights.com/topic/5967 ... ide/page-3

john

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

Post by galljj » Mon Aug 12, 2019 12:11 am

Sorry - I should have mentioned that the link to the latest version is in post # 66 on that page.

j

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 12, 2019 8:23 pm

John, I apprieciate your giving the SharpCap Manual a fresh reading and pointing out where some mistakes are made by new users of it. And I will continue to follow you as you go into the ToDo list. Also for the forseeable future I will read up on the this forum you've introduced me to (as well as keeping up with the help forum of SC) to learn anything more I can about EAA and perhaps about the deadening specific problem I've stumbled onto.

Your writing seems to suggest that I check the bit depth in the "STATUS" tab in the LIVE STACKING section. What bit depth would you recommend for a ZWO ASI 178 MC camera?
Also: use SAVE AS VIEWED which produces an 8 or 16 bit PNG file
Also: save as 16 bit stack which produces a 16 bit FITS file.
Also try x2 binning. Ive never used any binning so far. That may address my problem. We'll see in after the moon becomes less of an interference.

One critique I would offer of your work so far is that some (most) of the screen shots are very hard to read, even after magnifying or stretching the page. Perhaps the signal to noise ratio has fallen down. When I'm reading the SC manual I often have to use a 4 inch hand lense. But it is at least barely readable. Carl

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

Post by donstim » Mon Aug 12, 2019 8:41 pm

carlwagle wrote:
Mon Aug 12, 2019 8:23 pm

Also: use SAVE AS VIEWED which produces an 8 or 16 bit PNG file
There is no "SAVE AS VIEWED" in the current version of SharpCap. It is either "Save with Adjustments," which "will save the image with the Live Stacking adjustments applied (i.e. after histogram adjustments and colour adjustments have been applied) as an 8 or 16-bit PNG file (depending on bit depth of camera being used)" or "Save Exactly as Seen," which "will save the image exactly as shown on screen as an 8-bit PNG file. This will include the effects of both the live stacking histogram and colour adjustments and the display stretch if one is applied."

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

Post by carlwagle » Tue Aug 13, 2019 3:45 pm

"Your writing seems to suggest that I check the bit depth in the "STATUS" tab in the LIVE STACKING section. What bit depth would you recommend for a ZWO ASI 178 MC camera?" (add: capturing nebulosity or arms of galaxies).. Any illumination on this question would be greatly appreciated.

And you are right to call my attention to how I sloppily renamed one of the camera controls. The names mean the about the same thing but I should show more respect for AP and SC by using the designated name. The 'drifting ' careless way words are used leads to misunderstanding in the future. That is how I see the word stretch being twisted out of shape in AP today. Thank you John for your consideration. 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 » Wed Aug 14, 2019 11:16 am

Carl
What bit depth would you recommend for a ZWO ASI 178 MC camera?" (add: capturing nebulosity or arms of galaxies)
With a CMOS camera ( have access to ZWO, QHY, Altair models), I use:
  • 8-bit for lunar planetary, to achieve highest possible frames per second
  • 16-bit for deep sky, to acquire greatest detail possible
See my images in the Gallery sub-forum or my Astrobin https://www.astrobin.com/users/turfpit/

The results didn't come quickly (or easily) see viewtopic.php?f=16&t=596 . This shows progress over almost 3 years. The very last entries are a reprocess of data captured last October (9 months ago) - the result of recently understanding another element of post-processing (background extraction).

Have you considered capturing an image in the more traditional way? You could start with a more incremental approach:
  • light frames only and learn how to stack/process
  • add dark frames as a next step
  • move to flats/bias when you are ready
M27 is a good object to choose at this time of year - a bright object sitting in a rich star field. Once you have a grounding in the basics, then re-visit Live Stack.

As always, with this type of advice, YMMV (what works for me may not work for 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 Aug 14, 2019 7:06 pm

Thanks Dave. I have looked far into the Gallery and seen your included pictures more than twice before today. Yes, they do show a lot of progress.

You have helped me before. Most recently about May 8th this year: viewtopic.php?f=23&t=1628

Some things I learned at that time were, to store dark frames in The Library. They are easier to access from there. Old ones (those more than 3 hours old) should be deleted. There is less confusion as to WHAT was used. I never did learn for sure what That problem was. My guess is the camera quit making that hot, four square, pixel that even with a dark frame applied got repeated (like in ossilations) enough times to substitute for the normal stars needed to begin tracking. Perhaps there was an abnormality in the camera that finally burned itself out. I'm on guard for it to come back.

You write: "Have you considered capturing an image in the more traditional way? You could start with a more incremental approach:
..light frames only and learn how to stack/process"
What is the difference between a "light frame" and taking pictures of deep sky objects? I have taken many stacked pictures of several M#? objects, only star clusters, no nebulosity attempted before this failure of performance. But perhaps my difficulty with M051 should have been a warning. I have made good videos and JPEG pictures of the Moon. I'm presuming I've got stacking behind me. But when it comes to processing all I know is the little that comes with the JPEG pictures and I have not done anything with the Fits Files. What I first see on a Fits picture is what I got. And so far at this time no nebulosity has been seen on any of my Fitses.
I do agree that some kind of more basic approach to SC could have been provided by it. Perhaps some spots of practice and review. I feel like the user is expected to understand it all before doing anything. And my experience of unknowingly operating with the ZOOM Function left on at above 200% proves that such complete understanding may be needed. Sort of like if you are going to learn how to shoot a fully automatic rifle or do brain surgery,,,, you better know all there is to it!!
I will check to be sure that I an using a bit depth of 16. Can I set that up as my default condition using the provided SC Deep Sky Camera? I would like to get that done without having to set up a telescope and camera.

So far no one has spotted my problem in my camera settings I've provided. I bet it's 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 » Thu Aug 15, 2019 1:10 am

Carl
I do agree that some kind of more basic approach to SC could have been provided by it.
The basic approach is already built into SharpCap - just capture some frames as shown here

Capture1.JPG
Capture1.JPG (36.26 KiB) Viewed 44 times
Capture2.JPG
Capture2.JPG (37.86 KiB) Viewed 44 times

You decide the number of frames.
What is the difference between a "light frame" and taking pictures of deep sky objects
None. The image captured by the camera pointing at an object is called a light frame and is in effect a picture of the object the camera is pointing at. Because of the faintness of the object, little will be seen on the screen. This why multiple images are taken and then stacked - see viewtopic.php?f=18&t=1808.

[Note: a dark frame would use the same settings as a light frame and be captured with the cap on the telescope.
I feel like the user is expected to understand it all before doing anything.
The purpose of the SharpCap Manual is to describe the functionality within the software - it does not set out to teach you how to image. Buy a car - it will come with a manual - the manual describes what all the nobs, levers and lights do/mean - it does not teach you how to drive. Learning to drive would require a separate step of training (probably not from the person who sold you the car).

Here perhaps you could join a local astronomy club or attend workshops. I made my progress by attending 1-day workshops over a period of 2 years.
[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
From your capture settings file:
  • Output Format = FITS would be a better choice
  • Capture area is OK
  • Colour Space = RAW16 is the best setting for deep sky imaging (to get the most detail)
  • Gain, start off with a value halfway between the minimum and maximum available on the slider. This will need to be changed with experience.
  • Exposure =32s is a good start for M27.
I think local help will speed up your progress.

Dave

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 15, 2019 7:11 pm

Dave, I posted the following on your Aug 2nd WHY WE STACK. It's strange that I can't find that under this General Postings Site dated Aug 2nd..

Thanks that was really very interesting and the best directions for anyone having such problems as I have had that may in fact have to abandon SC in order to stack pictures dealing with nebulosity,,,, very encouraging too. And by chance you are illustrating with the very image I have been having trouble with, M27..

As I said earlier I can get a descent single JPEG picture (as good as yours) showing the faint image, so I take a train of them and stack them with some other program.

OK,, I will bookmark all this and save it for when I find out I will have to go further afield than using only SC. But I'm not going to give up on SC just yet unless someone tells me that I must. It could be PERHAPS all straightened out by holding down the CTRL KEY while opening onto my ZWO camera. Who knows?
Carl Wagle

Also Dave, I am an active member of the Greensboro Astronomy Club. They know that due to the membership coming from the NW side of the city that I'm actively trying to start a club on my side (SE) of the city and have about 3 new people that I have found nearby. They already own much better equipment than me but not knowing anything yet about AP. One does not even know how to set up her Equatorial Mount so that she only has to twist only one knob to manually track! I have opened up three very dark sky areas to the SE that are darker and closer in to even members of GAC to use.
There is one oldhand AP in the club, Paul Patterson. He is very good at it but he uses all the things outside of SC that you know about and I don't think he has any experience with SC,, but I will double check. I will also enquire if there are people familiar with SC who are not attending our club meetings.


ONE QUESTION: If I choose to capture one frame at a time (train) in Fits can I still use those frames outside of SC to make my own stacking? Right now I'm betting every frame but the first one in FITS will show no nebulosity, only the star field. But looking forward to trying this. Thanks again, 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 » Thu Aug 15, 2019 11:24 pm

Thanks Carl for the comments on the stacking of frames. I managed to demo the value of stacking without getting involved with the maths which is usually used on this topic.
may in fact have to abandon SC in order to stack pictures dealing with nebulosity
Not necessarily - SharpCap can be used in two ways:
  • As a traditional capture program, you capture light frames (images), darks and if required flats & bias frames. You then process these in typically Deep Sky Stacker and Photoshop (or GIMP) or software such as SiriL
  • By using the Live Stack feature, where images are captured and stacked, with the ability to perform limited processing on the fly. Additionally, Live Stack can save all the captured frames for processing in the way mentioned above.
This was created using Live Stack viewtopic.php?t=561 with a link to the image https://www.astrobin.com/full/330099/0/?nc=user. A single stack was created comprising 60x30s. 5 of these stacks were created and then combined using Deep Sky Stacker. The person who did this, Minos, I would consider a master at Live Stacking.

I only ever used Live Stack to create the material for the SharpCap 2.9 manual, I will revisit it one day. I have elected to follow a more traditional imaging route for now in the belief that I will develop a better understanding of the basic principles of imaging/processing.

Have a read at https://docs.sharpcap.co.uk/3.2/#The%20Histogram. Understand the histogram and you will be able to take control of your imaging. That was the single big step in my development.

This is a good basic book on the use of Deep Sky Stacker
https://www.amazon.co.uk/Star-Gazing-Gu ... way&sr=8-2

Dave

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