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31 July 2020 - Comet Registration video tutorial using APP 1.083-beta1 released.

30 July 2020 - APP 1.083-beta1 has been released introducing Comet processing! This 1st beta has comet registration. The stable release will also include special comet integration modes.

9 July 2020 - New and updated video tutorial using APP 1.081: Complete LRGB Tutorial of NGC292, The Small Magellanic Cloud by Christian Sasse (iTelescope.net) and Mabula Haverkamp

2019 September: Astro Pixel Processor and iTelescope.net celebrate a new Partnership!

LRGB stacking  

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(@pswilson1)
White Dwarf Customer
Joined: 6 months ago
Posts: 15
September 9, 2020 17:52  

I have been using APP successfully for my OSC stacking.  I am very satisfied with APP.

I got a new mono camera and LRGB filters to work with.  I didn't realize, no one is doing that with the F/2 RASA 8, but c'est la vie.

After many hours of processing, I ended up with a tilted stack.  Not totally surprising because on one of the sessions, the camera came off and was put back on the next night.  But I didn't know quite how to fix the tilt.  The corners themselves were not as rough as I might have expected.

Under "tools", I found a correct rotation tab.  I struggled with it, how does it work?  I got the image straighter than it had been and finally clicked "Save".  Well it saved, but in the process APP locked up, with both the CPU and memory tabs red against the max.  This I didn't expect, as I am now using a very powerful desktop computer.

When I tried to open the saved stack in Star Tools, Star Tools froze also!  So it would appear I really did something wrong.  Are there any special rules that apply to LRGB?  How do I straighten a tilted stack without harming anything?  I am currently, while I type this, re-running the stack from scratch.  I am new to LRGB, so I am NOT blaming APP.  Lol, with this hobby, it's never very long to my next screw-up!


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 2469
September 10, 2020 10:00  

If there was rotation, the final stack will show this based on the rotation of the reference frame. You should be able to simply rotate the frame by a specified number of degrees in the Batch Modify tool. That's the one you used?


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(@pswilson1)
White Dwarf Customer
Joined: 6 months ago
Posts: 15
September 10, 2020 15:41  

@vincent-mod  

yes, that's what I tried to use.  It was difficult to get it exactly level, kept going too much one way or the other.  I restacked over night, it's been running now for 12 1/2 hours and using 270 GB of drive space, which I have.  Today, I will watch the LRGB tutorial, which I didn't know about previously.  Perhaps I did something wrong, I had read that multi channel LRGB wasn't "that much different".  If using LRGB proves an unnatural process for an F/2 RASA, I will probably invest in the NB F/2 Baader filters.  By all accounts, the ASI1600 is a fine mono camera.


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 2469
September 15, 2020 09:22  

Excellent, let me know what the result was. Getting it exactly level can be hard indeed, I would then opt to do a minor crop instead of perfect rotation.


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(@pswilson1)
White Dwarf Customer
Joined: 6 months ago
Posts: 15
September 15, 2020 17:31  

I sure hate to give up on this, it was so much work, but I can't get a color image.  The 2nd attempt to stack the exposures took about 18 hours.  I was able to take the stack to Star Tools, which produced a very detailed black and white image and comical color.  I joked that I could sell the result for new, astro/modern art.

So I returned to see if I could process the image using APP tools.  But I really have in the past only tried the LP removal tool and I don't know how to use the LRGB tools.  Do I need to load in the stacked channels independently again, or use the combined stack?  I tried that and the program just was unresponsive.  Very discouraged with my first, labor intensive foray into LRGB.

 


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 2469
September 17, 2020 14:10  

The best thing is to have your L, R, G and B stacks separate first. Make them look nice and then loading them in again as "lights" (so now you only have 4 in total) to register, normalize them against each other. You go to the normalize tab and normalize them, then you click "save normalized frames" on the bottom of that tab. This way you know all of them are propery aligned and normalized. Then you go to tools and "RGB Combine" in which you can load your saved stacks as L, R, G and B and then produce a RGB result. You can play with each channel's contribution in the tool but for a first try I would just select the LRGB preset.


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(@pswilson1)
White Dwarf Customer
Joined: 6 months ago
Posts: 15
September 19, 2020 22:09  

I followed your advice and stacked a new target of LRGBs separately.  All 4, LRGB, stacked well with no errors.  The 4 stacks looked decent to me at least.

I subsequently took the individual stacks to Star Tools and tried to load them as LRGB.  ST gave me an error message about the stacks not having the same bitmap dimensions and said I must have binned 2x2, which I didn't, all the sub headers say 1x1. Honestly, I didn't understand the error message.  So I thought I would restack the Ls in case something was wrong there.

Back in APP when I try to select my L lights, APP from the previous session has made a file copy of each sub, so that when I go to load them, there are now 900 subs instead of 450.  What do I do?  Load all 900?  Tediously try to select every other sub that has the orignial, shorter header?  What is APP doing there?

I think I will try to combine LRGB in APP as you initially suggested otherwise, and in fact it's a skill I desire to develop.  Not understanding the arcane nuances of a software can be very frustrating for the uninitiated.


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 2469
September 20, 2020 11:51  

Mmm, I have no knowledge of startools, but the reason why you suddenly had double the data is very strange. It's difficult to see if that was caused by APP as startools was involved as well. APP normally never copies data twice.


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(@pswilson1)
White Dwarf Customer
Joined: 6 months ago
Posts: 15
September 21, 2020 23:00  

For anyone who stumbles in here.  Not sure which wrong stacking box I checked, but what I didn't know, if there are unwanted files that come in when you load, you can sort them already inside APP by using the little search magnifying glass icon at the upper right of the loading window.

When I used this, I was able to separate out the unwanted calibration files instantly.  Now at least I can attempt to restack and get all my subs at the same size, a problem I hadn't even realized could happen.


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