Struggling newcomer looking for guidance

Questions and answers about processing in StarTools and how to accomplish certain tasks.
ldipenti
Posts: 17
Joined: Fri Oct 16, 2020 1:13 pm

Struggling newcomer looking for guidance

Post by ldipenti »

Hello all,

I'm trying to learn how to process with ST, and have been trying both the stable and alpha versions on a new stack of the Helix Nebula.
The integration time is almost 18 hours under a very polluted bortle 9 sky, using a Samyang 135mm lens with a Nikon D500 DSLR, so the data is undersampled.
The mount I have is a SkyWatcher AZ-GTi in EQ mode, and the imaging was done with dithering & guiding.

I've recently upgraded from using Deep Sky Stacker to Astro Pixel Processor, and although I've read that the stacking quality of both are very similar, my personal experience told me another different story: I got MUCH better final results than using DSS. Stacking with APP and processing the image with starnet++ and photoshop is my current processing workflow but I want to get even better results with StarTools, as I've seen it's possible on several Youtube videos.

So, I've been trying with the Helix Nebula and I present you my currently best attempt and a simple test with my familiar tools, so you can compare. And just in case anyone feels like giving the data a go, I also added the stacked FITS file, and my session's log:

https://www.dropbox.com/sh/piqqsbtfngrz ... 1tpMa?dl=0

What am I doing wrong?

Thanks for any help!

Lucas.
mgutierrez
Posts: 37
Joined: Sat Oct 24, 2020 11:07 pm

Re: Struggling newcomer looking for guidance

Post by mgutierrez »

Hi Lucas,

I'm a newbie user with ST. This is a fast attempt. How does it look like? A bit noise perhaps :roll:
Helix_Nebula-Stack_03.jpg
Helix_Nebula-Stack_03.jpg (352.68 KiB) Viewed 625 times
Miguel
almcl
Posts: 184
Joined: Wed Jan 21, 2015 7:15 pm
Location: Shropshire. UK

Re: Struggling newcomer looking for guidance

Post by almcl »

Thanks for posting your data. I had a go with the latest edition (as of this afternoon 1.7.434) and the result is below.

There were some quite strong gradients which were cropped out and to speed up processing I binned to 35% although this wouldn't be something I'd normally do on under sampled data.

Until Ivo comes along with a much more expert opinion, see what you think?
Helix_Nebula-Stack.jpg
Helix_Nebula-Stack.jpg (130.39 KiB) Viewed 625 times
Skywatcher 190MN, ASI 2600 or astro modded Canon 700d, guided by OAG, ASI120, PHD2
mgutierrez
Posts: 37
Joined: Sat Oct 24, 2020 11:07 pm

Re: Struggling newcomer looking for guidance

Post by mgutierrez »

almcl wrote: Tue Oct 27, 2020 8:47 pm Thanks for posting your data. I had a go with the latest edition (as of this afternoon 1.7.434) and the result is below.

There were some quite strong gradients which were cropped out and to speed up processing I binned to 35% although this wouldn't be something I'd normally do on under sampled data.

Until Ivo comes along with a much more expert opinion, see what you think?
Helix_Nebula-Stack.jpg
better than mine! could you please explain the steps followed?
almcl
Posts: 184
Joined: Wed Jan 21, 2015 7:15 pm
Location: Shropshire. UK

Re: Struggling newcomer looking for guidance

Post by almcl »

Here you go.

Not everything I did is strictly approved (using the Superstructures module with a mask to cut back the noise, for example) and I had to have several goes at cropping to deal with the gradients.
The very last develop module is just to get the histogram away from the left edge (I think this is a direct consequence of the Superstructure Isolate action).

File loaded [E:\Astronomy\someone else's files\Helix_Nebula-Stack.fits].
Image size is 5062 x 3660
---
Type of Data: Linear, was not Bayered, or was Bayered + white balanced
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [Off]
Parameter [Outside RoI Influence] set to [15 %]
Parameter [RoI X1] set to [0 pixels]
Parameter [RoI Y1] set to [0 pixels]
Parameter [RoI X2] set to [5062 pixels (-0)]
Parameter [RoI Y2] set to [3660 pixels (-0)]
Parameter [Detector Gamma] set to [1.00]
Parameter [Shadow Linearity] set to [50 %]
--- Bin
Parameter [Scale] set to [scale 50.00% / +2.00 bits / +1.41x SNR improvement]
Image size is 2531 x 1830
--- Crop
Parameter [X1] set to [26 pixels]
Parameter [Y1] set to [28 pixels]
Parameter [X2] set to [2483 pixels (-48)]
Parameter [Y2] set to [1785 pixels (-45)]
Image size is 2457 x 1757
--- Wipe
Parameter [Synthetic Dark/Bias] set to [Off]
Parameter [Gradient Edge Behavior] set to [Absorb 50%]
Parameter [Synthetic Flats] set to [Off]
Parameter [Sampling Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [4 pixels]
Parameter [Gradient Falloff] set to [0 %]
Parameter [Synth. Bias Edge Area] set to [100 %]
Parameter [Gradient Aggressiveness] set to [75 %]
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [Off]
Parameter [Outside RoI Influence] set to [15 %]
Parameter [RoI X1] set to [0 pixels]
Parameter [RoI Y1] set to [0 pixels]
Parameter [RoI X2] set to [2457 pixels (-0)]
Parameter [RoI Y2] set to [1757 pixels (-0)]
Parameter [Detector Gamma] set to [1.00]
Parameter [Shadow Linearity] set to [50 %]
--- Crop
Parameter [X1] set to [319 pixels]
Parameter [Y1] set to [138 pixels]
Parameter [X2] set to [2109 pixels (-348)]
Parameter [Y2] set to [1537 pixels (-220)]
Image size is 1790 x 1399
--- Wipe
Parameter [Synthetic Dark/Bias] set to [Off]
Parameter [Gradient Edge Behavior] set to [Absorb 50%]
Parameter [Synthetic Flats] set to [Off]
Parameter [Sampling Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [5 pixels]
Parameter [Gradient Falloff] set to [0 %]
Parameter [Synth. Bias Edge Area] set to [100 %]
Parameter [Gradient Aggressiveness] set to [92 %]
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [3.5 pixels]
Parameter [Outside RoI Influence] set to [4 %]
Parameter [RoI X1] set to [938 pixels]
Parameter [RoI Y1] set to [740 pixels]
Parameter [RoI X2] set to [1031 pixels (-759)]
Parameter [RoI Y2] set to [876 pixels (-523)]
Parameter [Detector Gamma] set to [1.00]
Parameter [Shadow Linearity] set to [50 %]
--- Contrast
Parameter [Expose Dark Areas] set to [No]
Parameter [Compensate Gamma] set to [No]
Parameter [Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [5 pixels]
Parameter [Aggressiveness] set to [50 %]
Parameter [Dark Anomaly Headroom] set to [50 %]
--- HDR
Parameter [Small Detail Precision] set to [Max]
Parameter [Channels] set to [Brightness Only]
Parameter [Algorithm] set to [Optimize Soft]
Parameter [Dark/Bright Response] set to [Full]
Parameter [Detail Size Range] set to [211 pixels]
Parameter [Strength] set to [1.2]
--- Wavelet Sharpen
Parameter [Structure Size] set to [Large]
Mask used (BASE64 PNG encoded)



--- SNR-aware Wavelet Sharpening
Parameter [Scale 1] set to [100 %]
Parameter [Scale 2] set to [100 %]
Parameter [Scale 3] set to [100 %]
Parameter [Scale 4] set to [100 %]
Parameter [Scale 5] set to [100 %]
Parameter [Mask Fuzz] set to [4 pixels]
Parameter [Amount] set to [300 %]
Parameter [High SNR Size Bias] set to [85 %]
Parameter [Low SNR Size Bias] set to [0 %]
Parameter [Dark/Light Enhance] set to [50% / 50%]
--- Deconvolution
Parameter [Image Type] set to [Deep Space]
Parameter [Secondary PSF] set to [Off (Primary Only)]
Parameter [Primary PSF] set to [Moffat Beta=3.0 (Saglia, FALT)]
Parameter [Primary Radius] set to [1.5 pixels]
Parameter [Iterations] set to [11]
Parameter [Error Diffusion] set to [Off]
Parameter [Mask Fuzz] set to [8.0 pixels]
Parameter [Deringing] set to [50 %]
Mask used (BASE64 PNG encoded)

Mask used (BASE64 PNG encoded)


--- Shrink
Parameter [Mode] set to [Tighten]
Parameter [Halo Extend] set to [1 pixels]
Parameter [Iterations] set to [20]
Parameter [Regularization] set to [0.85]
Parameter [De-ringing] set to [2 pixels]
Parameter [UNKNOWN] set to [1.5 pixels]
Mask used (BASE64 PNG encoded)


--- Color
Parameter [Bias Slider Mode] set to [Sliders Reduce Color Bias]
Parameter [Style] set to [Scientific (Color Constancy)]
Parameter [LRGB Method Emulation] set to [Straight CIELab Luminance Retention]
Parameter [Matrix] set to [Identity (OFF)]
Parameter [Dark Saturation] set to [2.0]
Parameter [Bright Saturation] set to [Full]
Parameter [Saturation Amount] set to [200 %]
Parameter [Blue Bias Reduce] set to [1.00]
Parameter [Green Bias Reduce] set to [1.46]
Parameter [Red Bias Reduce] set to [1.11]
Parameter [Mask Fuzz] set to [1.0 pixels]
Parameter [Cap Green] set to [100 %]
Parameter [Highlight Repair] set to [Off]
Mask used (BASE64 PNG encoded)

{the mask here was just set to the nebula}


--- Super Structure
Parameter [Detail Preservation] set to [Linear Brightness Mask]
Parameter [Compositing Algorithm] set to [Multiply, Gamma Correct]
Parameter [Brightness, Color] set to [Only Brightness]
Parameter [Brightness Retention] set to [Off]
Parameter [Mask Fuzz] set to [36.0 pixels]
Parameter [Airy Disk Radius] set to [91 %]
Parameter [Gamma] set to [0.50]
Parameter [Detail Preservation Radius] set to [20.0 pixels]
Parameter [Saturation] set to [100 %]
Parameter [Strength] set to [100 %]
Mask used (BASE64 PNG encoded)


--- Wavelet De-Noise
Parameter [Grain Size] set to [6.0 pixels]
Parameter [Walking Noise Size] set to [1.0 pixels]
Parameter [Walking Noise Angle] set to [0]
--- Wavelet De-Noise
Parameter [Scale 1] set to [95 %]
Parameter [Scale 2] set to [95 %]
Parameter [Scale 3] set to [95 %]
Parameter [Scale 4] set to [95 %]
Parameter [Scale 5] set to [50 %]
Parameter [UNKNOWN] set to [10 %]
Parameter [Scale Correlation] set to [50 %]
Parameter [Color Detail Loss] set to [50 %]
Parameter [Uniform Grain Retention] set to [50 %]
Parameter [Grain Dispersion] set to [6.0 pixels]
--- Develop
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.00]
Parameter [Skyglow] set to [1 %]
Parameter [Digital Development] set to [Off]
Parameter [Blue Luminance Contrib.] set to [100 %]
Parameter [Green Luminance Contrib.] set to [100 %]
Parameter [Red Luminance Contrib.] set to [100 %]
Parameter [Dark Anomaly Headroom] set to [5 %]
Parameter [Dark Anomaly Filter] set to [6.0 pixels]
File saved [E:\Astronomy\someone elses files\Helix_Nebula-Stack.tiff].
--- Crop
Parameter [X1] set to [302 pixels]
Parameter [Y1] set to [253 pixels]
Parameter [X2] set to [1630 pixels (-160)]
Parameter [Y2] set to [1362 pixels (-37)]
Image size is 1328 x 1109
File saved [E:\Astronomy\someone elses files\Helix_Nebula-Stack.tiff].
Skywatcher 190MN, ASI 2600 or astro modded Canon 700d, guided by OAG, ASI120, PHD2
ldipenti
Posts: 17
Joined: Fri Oct 16, 2020 1:13 pm

Re: Struggling newcomer looking for guidance

Post by ldipenti »

mgutierrez wrote: Tue Oct 27, 2020 9:15 pm
almcl wrote: Tue Oct 27, 2020 8:47 pm Thanks for posting your data. I had a go with the latest edition (as of this afternoon 1.7.434) and the result is below.

There were some quite strong gradients which were cropped out and to speed up processing I binned to 35% although this wouldn't be something I'd normally do on under sampled data.

Until Ivo comes along with a much more expert opinion, see what you think?
Helix_Nebula-Stack.jpg
better than mine! could you please explain the steps followed?
Thanks a lot for taking the time to review my data! Your results are a lot better than mine, so I would like to ask if you saw any particular issue with my stacked data (always taking into account that was acquired from a white zone location), and if so, if that forced you to take uncommon measures to process it? I ask because on my 3 or 4 tries I was following along Guy's recommendations (or at least trying to) and for me the process was so painful and slow and the results were so little gratifying that I'm supposing I messed up big time in some step.

The APP+Starnet+Photoshop image that I left on the dropbox link to my eyes has lots of detail and I could get it with very little effort. APP's background extraction tool is awesome, and with StarNet++ I remove the stars and process the rest on photoshop without worrying about bloating stars or having to do star masks, and as a last step I add the stars back and that's it. I'm aware that this procedure has its own problems and that's why I aim to do better with StarTools.

BTW, thanks for the detailed procedure, I'll give it a go to see if I can get similar results.
almcl
Posts: 184
Joined: Wed Jan 21, 2015 7:15 pm
Location: Shropshire. UK

Re: Struggling newcomer looking for guidance

Post by almcl »

I am by no means an expert, so take what follows with a good pinch 0of salt but

There was a strong green cast to the data after the 1st Autodev. Had APP (I have never used this, so don't know what it does) applied any colour balancing, normalisation, black point resetting or channel aligning? StarTools works best if the data has only been stacked and no other manipulations carried out.

Once wipe had dealt with this, we were left with a lot of gradients. With a target like this it's not too difficult to crop these out, but if you have any way to reduce light pollution interfering with the sub, like a longer lens hood or screens or whatever, this might help.

Apart from these, I didn't do anything that I don't usually do with my own data, although it might be worth experimenting with the parameters in the 2nd Autodev (the one that comes after Wipe). In particular adjusting the ROI, setting Ignore Fine detail to 2 or 3 and Outside ROI to 5% or less can make a big difference to the background noise and detail in the nebula. In the HDR module, Reveal core and then reducing the detail size range down to 300 or less, can also make big difference.

Hope this helps?
Skywatcher 190MN, ASI 2600 or astro modded Canon 700d, guided by OAG, ASI120, PHD2
ldipenti
Posts: 17
Joined: Fri Oct 16, 2020 1:13 pm

Re: Struggling newcomer looking for guidance

Post by ldipenti »

Thanks for your advice! I'll have a second go on your step by step procedure so I can tinker with those settings.

Regarding the green cast, I supposedly stacked using APP's recommended settings for StarTools. I think I drizzled it so I can also change the integration type to standard and see what happens.

Regarding the gradients, I always use the lens original hood that's quite large. At my latitude, the Helix Nebula is really up in the sky, and I captured it around +/- 2h its highest point every night so I guess that's the best I can do. Maybe some nights I had some really poor seeing that that messed up the entire stack, could that be the case?

Anyways, thanks again for your help!
ldipenti
Posts: 17
Joined: Fri Oct 16, 2020 1:13 pm

Re: Struggling newcomer looking for guidance

Post by ldipenti »

Oh, I forgot one thing. My original question is about getting at least similar results as my usual workflow (APP's post processing tools + StarNet + Photoshop), and to my eyes, your attempt is very near but I see more fine details on my version. The question is: is that detail "real" or is it made up because I used tools that make aesthetic changes instead of signal processing? Maybe Ivo could also chime in here.

Thanks!
Lucas.
fmeireso
Posts: 26
Joined: Mon Sep 28, 2020 8:46 pm

Re: Struggling newcomer looking for guidance

Post by fmeireso »

I tried the stack too...good excercie because processing is not really one of my strongest points.

There is some nasty gradiënt or noise of both i could NOT get quick out but anyhow the nebulae itself came out pretty well imo.

I did not really take much time, just a quick go through ST
Attachments
Helix_Nebula-Stack (Large).jpg
Helix_Nebula-Stack (Large).jpg (294.01 KiB) Viewed 547 times
Last edited by fmeireso on Thu Oct 29, 2020 7:25 am, edited 1 time in total.
Post Reply