Using different settings in Autostakkert 3

this is the main message area for anything solar :)
Post Reply
User avatar
Montana
Librarian
Librarian
Posts: 34559
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17666 times
Been thanked: 8787 times

Using different settings in Autostakkert 3

Post by Montana »

I am probably saying something here that maybe all of you take for granted because I seem to be the only person struggling to stack images from larger apertures. It all started when I noticed that my eyes could see detail in the video but the stacked images never ever showed what my eye could see.

I have done two tests so far, I have yet to try on Halpha but I think I have other problems there as well.

First CaK with the C11 stopped to 9 and 3/4 inch to get rid of aberration. These were taken with the 2.5x Powermate but even with a flat you can see that processing in the middle is compromised. 6000 frames and 5% taken for stack

NR = Quality estimator - Noise Robust
Br = brightness setting in the AP (alignment point box)

As you can see in the CaK it is very important to use a high NR and I feel a brightness on the high side. This is very different to my standard of NR 4 and Br 35 I would use with the TEC.
2020-04-15 ASK3 test CaK 2-5x.jpg
2020-04-15 ASK3 test CaK 2-5x.jpg (3.02 MiB) Viewed 5201 times
However for white light NR7 is still the best but I thought the Br on the low side was maybe better? These are still horrible pictures and look nothing like granulation so please don't comment about that. WL full aperture Baader film 3x Barlow (Televue). 6000 frames and 5% stack
2020-04-22 WL 3x test.jpg
2020-04-22 WL 3x test.jpg (1.52 MiB) Viewed 5201 times
So I tried NR7 and Br10 on last years problem WL file and it was a reasonable improvement, so I feel I am slowly making progress.
Sun_095036_12_05_2019 good_lapl7_ap6146 a.jpg
Sun_095036_12_05_2019 good_lapl7_ap6146 a.jpg (565.94 KiB) Viewed 5201 times
But still no where near a single frame
Frame 813 a.jpg
Frame 813 a.jpg (1.33 MiB) Viewed 5201 times
So the message here is your image is only as good as the stack, if the stack is rubbish then it doesn't matter what processing you do, it will still be rubbish. Experiment with the ASK3 settings.
My rule of thumb is that the stack should be a good representative of what your eye can see in the video or a single frame, it shouldn't be worse than the input. But maybe you all know this anyway and you will laugh at me, but I thought I would share.

Alexandra


Freddie
Ohhhhhh My!
Ohhhhhh My!
Posts: 149
Joined: Sat Jul 28, 2018 9:36 am
Has thanked: 38 times
Been thanked: 185 times

Re: Using different settings in Autostakkert 3

Post by Freddie »

Can’t comment on your CaK but for your WL image, have a look to see how many alignment points are used (assuming you don’t apply them manually) at the two different min bright settings. I can’t imagine it will be a very big difference between the two as it is not a particularly big brightness change.


Freddie
Ha: 152mm, Quark, ASI174m
WL: CPC9.25, ASI120m
User avatar
rsfoto
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 6159
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México
Has thanked: 9401 times
Been thanked: 5561 times

Re: Using different settings in Autostakkert 3

Post by rsfoto »

Montana wrote: Tue Apr 28, 2020 5:36 pm I am probably saying something here that maybe all of you take for granted because I seem to be the only person struggling to stack images from larger apertures. It all started when I noticed that my eyes could see detail in the video but the stacked images never ever showed what my eye could see.

I have done two tests so far, I have yet to try on Halpha but I think I have other problems there as well.

First CaK with the C11 stopped to 9 and 3/4 inch to get rid of aberration. These were taken with the 2.5x Powermate but even with a flat you can see that processing in the middle is compromised. 6000 frames and 5% taken for stack

NR = Quality estimator - Noise Robust
Br = brightness setting in the AP (alignment point box)

As you can see in the CaK it is very important to use a high NR and I feel a brightness on the high side. This is very different to my standard of NR 4 and Br 35 I would use with the TEC.

2020-04-15 ASK3 test CaK 2-5x.jpg

However for white light NR7 is still the best but I thought the Br on the low side was maybe better? These are still horrible pictures and look nothing like granulation so please don't comment about that. WL full aperture Baader film 3x Barlow (Televue). 6000 frames and 5% stack

2020-04-22 WL 3x test.jpg

So I tried NR7 and Br10 on last years problem WL file and it was a reasonable improvement, so I feel I am slowly making progress.

Sun_095036_12_05_2019 good_lapl7_ap6146 a.jpg

But still no where near a single frame
Frame 813 a.jpg

So the message here is your image is only as good as the stack, if the stack is rubbish then it doesn't matter what processing you do, it will still be rubbish. Experiment with the ASK3 settings.
My rule of thumb is that the stack should be a good representative of what your eye can see in the video or a single frame, it shouldn't be worse than the input. But maybe you all know this anyway and you will laugh at me, but I thought I would share.

Alexandra
Hi Alexandra,

Interesting. Would you upload the videos somewhere ? I would like to try them in AviStack.

Or you can send them via wetransfer wich accepts up to 2GB free.

Thanks


regards Rainer

Observatorio Real de 14
San Luis Potosi Mexico

North 22° West 101°
User avatar
AJamesB
Im an EXPERT!
Im an EXPERT!
Posts: 372
Joined: Thu Jan 30, 2020 9:21 pm
Location: Maui, Hawaii
Has thanked: 1150 times
Been thanked: 630 times

Re: Using different settings in Autostakkert 3

Post by AJamesB »

My rule of thumb is that the stack should be a good representative of what your eye can see in the video or a single frame
My final stacks always look worse than my better/best individual frames, but after deconvolution/sharpening they then look better than the best frames. Could be another area to look at for improvement of final images.

Only other thing I can think of is what Freddie mentioned, looking at the number and size of alignment/stacking points you use. If detail is good, I use small alignment points, and a lot of them, to try and isolate the good pockets of seeing. If too large they sometimes can get lost amongst the rest of the average seeing.

Would be fun to play with a video of the best 5-10% of the 6,000 frames to see what we can do with it.


Lunt ls100tha single stacked + hinode solar guider on ioptron cem26 mount
asi178mm
asi294mm
2x, 3x, and 4x telecentrics
0.6x and 0.4x telecompressors
Bruce G
Ohhhhhh My!
Ohhhhhh My!
Posts: 177
Joined: Mon Jul 16, 2018 8:18 pm
Has thanked: 128 times
Been thanked: 121 times

Re: Using different settings in Autostakkert 3

Post by Bruce G »

Are the two sunspot details images straight out of AS3? The first one looks like it has deconvolution artifacts more than stacking artifacts. The second one looks much better.

The brightness level should only affect the number of alignment points that are produced when you click Place AP grid. Try setting the number very low on a full disk image some time and watch what happens along the edge of the Sun when the AP grid is generated.

Just out of curiosity, About how many alignment points do you shoot for?


christian viladrich
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 2150
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Has thanked: 1 time
Been thanked: 2712 times
Contact:

Re: Using different settings in Autostakkert 3

Post by christian viladrich »

Hello Alexandra,
It is difficult to comment on these since we would need to know what are the other settings of AS3 ?
- use of Local / Global ?
- use of double stack reference ?
- AP Size ?

The "min brigthness" adjustement is just to say to AS not to put any alignement point on places of the image where the intensity is lower that "min brightness". If set too high the darkest regions are not considered.So this might be an image of very dark images (like Ca K).
Have you checked whether you have alignment points all over the image ?


Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 14204
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK
Has thanked: 8415 times
Been thanked: 8161 times

Re: Using different settings in Autostakkert 3

Post by Carbon60 »

Hi Alexandra,

As Christian says, the brightness adjustment changes the threshold that defines where alignment points are placed. I adjust this (upwards) to avoid placing points in the blackness of space for FD images or prom shots. I've never adjusted the NR setting and just use the mid-range. Maybe I should take more notice of this.

This is a snapshot of my settings, rightly or wrongly.....
Settings.jpg
Settings.jpg (148.25 KiB) Viewed 5116 times
Stu.


H-alpha, WL and Ca II K imaging kit for various image scales.
Fluxgate Magnetometers (1s and 150s Cadence).
Radio meteor detector.
More images at http://www.flickr.com/photos/solarcarbon60/
User avatar
MapleRidge
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 10199
Joined: Fri Jan 13, 2012 11:58 pm
Location: Cambray, ON Canada
Has thanked: 64 times
Been thanked: 4340 times
Contact:

Re: Using different settings in Autostakkert 3

Post by MapleRidge »

Great review of the settings in the software...a nudge for me to look at mine !!!

Brian


Brian Colville

Maple Ridge Observatory
Cambray, ON Canada

Photos: https://www.flickr.com/photos/185395281@N08/albums

10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM

2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
User avatar
marktownley
Librarian
Librarian
Posts: 42269
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20424 times
Been thanked: 10243 times
Contact:

Re: Using different settings in Autostakkert 3

Post by marktownley »

Hi Alexandra,

So, my understanding of what the different settings do and how I use them based on what I do.

Improved tracking feature if de-selected means when the software is doing the stabilisation routine, does it using 2x2 binning, if it is selected then no binning used. Deselected has the advantage of speed being quicker, selected means it will take 4 times longer (remember an image is 2 dimensional). Deselected is better if the image is jumpy (scope shake) or the seeing poor, selected in this situation can take a verylong time, and sometimes won't work. I generally only use selected if I have got particularly good data, or, don't have time constraints for processing (which I often do!)

Laplace I think you are going wrong here Alexandra in places. If look at the numbers says the following; 8 focuses on big features (resized data), 7 oversampled data, 6-4 normal range, 3 -2 focus on very small (high SNR data!). Lets think about what this is telling us:
8 would be the setting used if a files native frame size was (for example) 640x480 but the software resampled it, so it played back at 1280x960. This is the equivalent of if you looked a picture in photoshop at 200% zoom, the image is twice the size but only the same amount of detail is there so it looks blocky and lacking in resolution. I'm not aware of capture software that does this, so my advice avoid.
7Refers to oversampled data, this is when the pixel size of the camera is too small to ideally sample at the scale you are imaging at (Nyquist), so, for example if you were using an ZWO290M to image with a Quark. The camera is suited to imaging at f15 ideally, but with a Quark you are f30. Poor seeing also mimics the effect of oversampling - the blurring of data, so, looking at the WLs you post it makes perfect sense if you are pushing it with the seeing, and, in the WL you are imaging at f35 which is borderline oversampling. So, to me, makes perfect sense you are getting best results in WL at this value.
6-4 Normal range - Seeing is OK, not particularly oversampling or undersampling. For my CaK and Ha I normally use 4, as I make a point that pixel size is good for image scale (sampling - longer focal ratios = bigger pixel size, smaller focal ratios = smaller pixel size). If the seeing is bad I find for me '5' works better. I only ever use '6' on prom shots.
3-2 If when using AS3 I find I have some files that are particularly good data (rare!) I set laplace to 3 as it has a better SNR, generally this would only be in CaK as features have a higher constrast than the more subtle grades of Ha. Caveat!!! Setting too low and AS3 focuses on noise and will look at those transient pixels of noise and stack these resulting in noisier final images. 99% of the time I never use '3' and 100% of the time do not use '2' Someone using a IMX174 chip to do full disks (where the disk ends up being say 700-800 pixels mid frame) with a short focal length scope would do well to use lower (3-4) laplace values as the image is undersampled.

I always use 'local' rather than 'global'. I have read people get good results from global in really poor seeing, the software uses the frame as a whole, rather than alignment points to determine the reference frame.

Double stack reference I don't find any improvement in using it, it does however take longer to process a file, so again I avoid.

Auto size I always use checked.

Min Bright I always have set to zero now, faffed around with it in the past and found the only thing it does is reduce processing time as fewer APs are being placed (in the black sky for example). Sometimes, particulary with proms the sky background can have an uneven chess board gradient to it and if this the case and really want to get that image I may raise the value to reduce it.

AP size My general rule, the worse the seeing the higher the value. For my Ha and CaK full disks under normal conditions (laplace4) I use a AP size of 48 and 'multi scale', this gives me around 17000 alignement points. This is with the 9.1Mp Grasshopper, with the 2.3Mp (IMX174) Grasshopper which I use at F20-30 I use the same size. If the data is brilliant raw data I may go for 24 for the AP size, if the data is bad I raise the value beyond 48. All seeing dependent.

Looking at the pics you have put up I would go with a laplace of 7 for the whitelights, however looking at the CaK (I think!) you're miles off with a laplace of 2 - the data definitely isn't high SNR! - maybe a 5, possibly a 6, but it doesn't look good seeing to me. Poor seeing effectively has the effect of gaussian blur on the data we record, and this has the same effect as oversampling.

I would go as far as to build on your conclusion, the final image is only as good as the stack and the stack is only as good as the seeing. My take in this to everyone is don't go chasing ghosts in seeing. I often see great views on the monitor - but, this is rarely (in my conditions) the whole image just a part, and that is where the eye is drawn. My eye is always drawn to the bottle of 18 year old single malt on the shelf in the shop, but in reality i'm more likely to come out with the 12 or 15 year old...

Just my thoughts and ramblings!

Mark


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
User avatar
Montana
Librarian
Librarian
Posts: 34559
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17666 times
Been thanked: 8787 times

Re: Using different settings in Autostakkert 3

Post by Montana »

Thanks everyone, I have never really understood all the points in ASK3 and wanted to investigate, so thank you Mark for a wonderful desciption of what everything means.

I have seen appalling videos on the web and then seen miraculous stacks they have produced from them (I've thought WOW mine are better than that!). I have found it unbelievable when I see lovely detail by eye in my videos compared to theirs and yet my stacks are rubbish. How do they do it?Particularly like in the above example of the sunspot, image one is a stack (with dust bunnies and all, yes sorry about that) and the second is a single frame from the video.

So, the take home message from you guys is - don't believe the videos on the web? you will never get a good stack unless the video is perfect?

So some points to answer:
It is impossible to upload and share a video, the sunspot is 9GB and the CaK or WL videos are 13GB, that would take me 12hrs to upload somewhere.

The change between brightness at 10 to br at 40 was about 5,800 alignment points to 6,100, so not much difference. I usually use AP size of 35.

Yes, stacks always look worse than the video until you sharpen it, but really the sharpened image should look just as good (not worse) than the best frames in the video. The first sunspot picture is a stack, the second is one single frame only. For this video it was better not to stack but work on one frame only.

I've only ever used local, results from global were always terrible so never used this.

never heard of the double stack ref before?

I wanted to try Avistack but I can't use it anymore as it says that I do not have a licence to use it.

Thanks for your help, I guess I need perfect videos which will never happen :(
Alexandra


User avatar
Radon86
Almost There...
Almost There...
Posts: 779
Joined: Sat Mar 23, 2019 10:05 pm
Has thanked: 745 times
Been thanked: 660 times

Re: Using different settings in Autostakkert 3

Post by Radon86 »

Hello Alexandra/Montana,

I have a similar problem with Autostakkert!3. It is usually really good. However, I still don't know how the frames are assessed in terms of quality, and which frames are good, and which frames are bad. I tried scrolling through the video file after Step 2: Analysis. The window says the frames are arranged in order of quality, but I don't know if it can do that so quickly, sorting in order over 1000 frames in a matter of seconds?

I came across one of GreatAttractor's other software which gives you more control - Stakistry. You can select the frames you want, and I suppose give you the option of just stacking those. It might take longer, but in the current lockdown, unless you are working long hours, there is time to try this out. I will try this out.

https://github.com/GreatAttractor/stackistry.

https://www.youtube.com/watch?v=_68kEYB ... L39z78zwdE

If you look at a video file, there is sometimes lots of movement from 1 frame to another, with a lot of blurring. It would be interesting to correlate the movement of the frame with respect to local or atmospheric conditions, including the jetstream. Measuring the movement in number of pixels could be possible.

Thanks for your helpful advice, Alexandra, I will post my Quark calibration files when I can manage to go through those videos !!
:band :)

Magnus.
London


Solar: H-alpha": Quark Chromosphere filter; Baader white light filters
Scopes: Altair Astro Travel ED70mm (F 420mm, D=70mm);; Skywatcher 90mm (F 910mm D=90mm); GSO focuser;;Altair Astro 60mm guidescope (D=60mm,F=225mm)
Cameras: ASI120mm-S,ASI174mm
Mount: SW HEQ5 Pro, SW EQ3 Pro Synscan (SW = Skywatcher),Vixen Polarie tracker (portable setup)
Accessory: SW Auto-focuser
User avatar
marktownley
Librarian
Librarian
Posts: 42269
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20424 times
Been thanked: 10243 times
Contact:

Re: Using different settings in Autostakkert 3

Post by marktownley »

Boso36 wrote: Thu Apr 30, 2020 12:31 pm I still don't know how the frames are assessed in terms of quality, and which frames are good, and which frames are bad.
Frames are assessed for quality in terms of their overall contrast, the sharpest frames will have the highest contrast, a poorer frame has lower contrast as details are blurred due to the seeing.


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
User avatar
Radon86
Almost There...
Almost There...
Posts: 779
Joined: Sat Mar 23, 2019 10:05 pm
Has thanked: 745 times
Been thanked: 660 times

Re: Using different settings in Autostakkert 3

Post by Radon86 »

Hi Mark,

Does Autostakkert!3 actually rearrange the frame order according to the quality graph in the centre of the main program window ? When you scroll frame by frame on the right window (the Image video), is the frame you see as you go from frame to the next frame, ranked in order ?

Thanks.
Magnus


Solar: H-alpha": Quark Chromosphere filter; Baader white light filters
Scopes: Altair Astro Travel ED70mm (F 420mm, D=70mm);; Skywatcher 90mm (F 910mm D=90mm); GSO focuser;;Altair Astro 60mm guidescope (D=60mm,F=225mm)
Cameras: ASI120mm-S,ASI174mm
Mount: SW HEQ5 Pro, SW EQ3 Pro Synscan (SW = Skywatcher),Vixen Polarie tracker (portable setup)
Accessory: SW Auto-focuser
User avatar
banjo
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1465
Joined: Sat Sep 17, 2016 12:38 pm
Location: France
Has thanked: 2090 times
Been thanked: 2859 times

Re: Using different settings in Autostakkert 3

Post by banjo »

Good morning all,
I may be off topic, translation problems.
I note that the quality value is not always optimum, if we scroll image by image we see that sometimes bad image is in the first positions.
Another factor to take with it is the number of images stacked in the end, I sometimes take only 20 to 100 images rather than percentages, you will also have to try that.
On my message today the photo "soleil-b-29avril20" is only the stacking of 33 images out of 1000.
sorry if my message is unrealistic, google translator is used.
Paul


bresser/messier 150/1200 (or 200/1800 Istar ) Mod -D-Erf 160mm intern-glasspath 1.25-etalon Pst barlow X2 ASI174
https://astropol.pagesperso-orange.fr/b ... 9/best2019
sorry for my English translators google :mrgreen:
Bruce G
Ohhhhhh My!
Ohhhhhh My!
Posts: 177
Joined: Mon Jul 16, 2018 8:18 pm
Has thanked: 128 times
Been thanked: 121 times

Re: Using different settings in Autostakkert 3

Post by Bruce G »

Mark - Thanks so much for the very helpful AS info

Magnus - AS does rearrange the frames. In the example below, I have performed the analysis on a 1000 frame SER file. In the image frame on the right, note that I moved the Frames slider just a bit to the right and that the frame number window to the right of the slider says that it's positioned on the 21st frame. Since the analysis has finished, this is now the 21st best frame in the file. The blue arrow points to the frame information area, providing more details. The actual frame number (in the original file) was #676. It is now placed as number 21 out of 1000 frames.

AS3 reordering.jpg
AS3 reordering.jpg (843.45 KiB) Viewed 4975 times
One other important AS tip. Now and then AS will choose a frame as having high quality when it actually doesn't. A bird flying by can cause the problem for example. Basically, AS (and SharpCap too, but I don't know about FireCapture) treats the difference between darkest and lightest as the measure of contrast. One time I accidentally walked in front of the telescope and the frames were selected as being very high quality.

When it is necessary to remove a few frames, particularly random frames, from analysis, you can scroll through the frames using the Frames slider. Click in the slider area. You can then use your arrow keys to move through the file one frame at a time. If you know about where the problem is, go there using the thumb of the slider, then use the arrow keys to find the problem frame(s). To eliminate a single frame, press the space bar. The green area under the slider will turn red, indicating that the frame will be skipped. You might have to click on the slider again to keep scrolling through the file. Eliminate all problem frames _before_ doing the Analyze operation. Usually what happens though is that you realize that something has gone badly wrong only after seeing the stack, then you have to go back, find the problem frames, nuke them, and start with Analyze again.
Last edited by Bruce G on Thu Apr 30, 2020 10:43 pm, edited 8 times in total.


User avatar
rsfoto
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 6159
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México
Has thanked: 9401 times
Been thanked: 5561 times

Re: Using different settings in Autostakkert 3

Post by rsfoto »

Hi Alexandra,

You wrote
I wanted to try Avistack but I can't use it anymore as it says that I do not have a licence to use it.
It is freeware and there is no license needed.

Here you can download the AviStack 2.0 version which is the one I use

http://www.avistack.de/download.html


regards Rainer

Observatorio Real de 14
San Luis Potosi Mexico

North 22° West 101°
User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: Using different settings in Autostakkert 3

Post by Merlin66 »

Another thought I have is that when long AVI’s are used, say 3000 frames the “best” 100 or 5% etc will be taken from the whole AVI - some may be at the beginning, some in the middle and some at the end. To me this could lead to surface, or prom movements being blurred due to movement in the detail during the AVI.
What if a series of shorter AVI’s were taken, the best from each then used to make up an image. We could then compare each image and look at the result of adding them together.
Make any sense?????


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
User avatar
Radon86
Almost There...
Almost There...
Posts: 779
Joined: Sat Mar 23, 2019 10:05 pm
Has thanked: 745 times
Been thanked: 660 times

Re: Using different settings in Autostakkert 3

Post by Radon86 »

Bruce G wrote: Thu Apr 30, 2020 3:04 pm Mark - Thanks so much for the very helpful AS info

Magnus - AS does rearrange the frames. In the example below, I have performed the analysis on a 1000 frame SER file. In the image frame on the right, note that I moved the Frames slider just a bit to the right and that the frame number window to the right of the slider says that it's positioned on the 21st frame. Since the analysis has finished, this is now the 21st best frame in the file. The blue arrow points to the frame information area, providing more details. The actual frame number (in the original file) was #676. It is now placed as number 21 out of 1000 frames.


AS3 reordering.jpg

One other important AS tip. Now and then AS will choose a frame as having high quality when it actually doesn't. A bird flying by can cause the problem for example. Basically, AS (and SharpCap too, but I don't know about FireCapture) treats the difference between darkest and lightest as the measure of contrast. One time I accidentally walked in front of the telescope and the frames were selected as being very high quality.

When it is necessary to remove a few frames, particularly random frames, from analysis, you can scroll through the frames using the Frames slider. Click in the slider area. You can then use your arrow keys to move through the file one frame at a time. If you know about where the problem is, go there using the thumb of the slider, then use the arrow keys to find the problem frame(s). To eliminate a single frame, press the space bar. The green area under the slider will turn red, indicating that the frame will be skipped. You might have to click on the slider again to keep scrolling through the file. Eliminate all problem frames _before_ doing the Analyze operation. Usually what happens though is that you realize that something has gone badly wrong only after seeing the stack, then you have to go back, find the problem frames, nuke them, and start with Analyze again.
Just looking at Stakistry to isolate frames and have a more controlled way of assessing individual frames.
Thanks for this, I shall have to investigate AS!3 more.

Magnus


Solar: H-alpha": Quark Chromosphere filter; Baader white light filters
Scopes: Altair Astro Travel ED70mm (F 420mm, D=70mm);; Skywatcher 90mm (F 910mm D=90mm); GSO focuser;;Altair Astro 60mm guidescope (D=60mm,F=225mm)
Cameras: ASI120mm-S,ASI174mm
Mount: SW HEQ5 Pro, SW EQ3 Pro Synscan (SW = Skywatcher),Vixen Polarie tracker (portable setup)
Accessory: SW Auto-focuser
Post Reply