Help doing large mi...
 
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Help doing large milkyway mosaic  

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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
June 16, 2019 17:19  

Hi,

I want to do a complete milkyway mosaic as soon as all panels are done. so far there are 12, done with Nikon D750 and a Sigma Art 40mm lens. With PTGUI Pro (testversion) it looks like this:

2019 06 13 16 39 34 Greenshot

with APP I stacked all panels separateley and played with parameters:

3: crucial and sensitive, so far best at 1500 to me

4: triangles takes long, penatgons works but see results below

it is the same optics and using mosaic mode APP forces to do so.  with scale I tried from 1 to 15 which seemd to work best,

used calibrated projetive mostly since the mosaic is over 200 degress across

flip x/y =? did not see a difference so quit using it

played with dist.margin, saw no effect

5: used advanced and mostly equitang. projection

6. default mostly, for I wanted to see if it works at all. scaled it to 0.1 to save time

the results were not encouraging to me so far:

with 7 panels I got this for example:

2019 06 13 08 55 52 Greenshot

with 12 this:

2019 06 13 13 58 25 Greenshot

after two days working on it I decided to make a break and next week restart from scratch

What am I missing? Any advice(es)? With PTGUI I need to give the program some controlpoints for a few panels it just cannot stitch without help. APP is really usually good at this, maybe this is too much.  

best,

stefan


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(@vincent-mod)
Quasar Moderator
Joined: 2 years ago
Posts: 1040
June 16, 2019 17:25  

I have to say that I'm not sure about the status of milky-way mosaics (@mabula-admin). This is already a pretty old post which might clarify some things ( https://www.astropixelprocessor.com/community/main-forum/distorted-milky-way-mosaic/#post-1384) but I have to ask Mabula about the best settings and if a better projection is still in the works..

I personally got it to work with some experimentation, but also that wasn't straight-forward and more a bit of luck playing around with the settings. Will get back to this shortly!

WebVersion

This post was modified 6 months ago by Vincent Groenewold - Moderator

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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
June 17, 2019 13:59  

Hi vincent,

I did many mosaics, which worked well, but none was wider than like 50 degress. 

I hope Mabula knows something, could just be it ain't possible with APP yet

Stefan


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(@vincent-mod)
Quasar Moderator
Joined: 2 years ago
Posts: 1040
June 17, 2019 14:20  

Yes, I'm simply not sure about it. I messaged him and he should be getting back to it shortly.


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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
June 25, 2019 09:07  

gave it another try, step by step: there is no way for me to prevent this:

when increasing the number of panels this crazy distortion gets worse no matter what I do. There is no rectangular projetion, only in the beginning it seems


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(@dav78)
Main Sequence Star Customer
Joined: 1 year ago
Posts: 43
June 25, 2019 09:56  

Have you tried by choosing the reference image in the center of the mosaic ?

You could also try this : make several mini mosaic, let's say 4 to 6 panels each, and the process the resulting panels to make the whole mosaic ? Just an idea 😉 


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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
June 25, 2019 18:37  
Posted by: Dav78

Have you tried by choosing the reference image in the center of the mosaic ?

You could also try this : make several mini mosaic, let's say 4 to 6 panels each, and the process the resulting panels to make the whole mosaic ? Just an idea 😉 

hi, yes, tried it, curverture comes later then when adding more. adding them to a set of 3 and then stacking these did not work either, registration failure. at least I tried with the settings I permutated before which I guess are all except maybe a few strange combinations

stefan 


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(@ralph)
Main Sequence Star Customer
Joined: 7 months ago
Posts: 27
June 27, 2019 07:18  

A "me too" post here...

I get good registration, but the projection model turns it into something that I'm not after. How about something like a Mollweide projection?


(@vincent-mod)
Quasar Moderator
Joined: 2 years ago
Posts: 1040
June 27, 2019 20:30  

Yes I think this should be easier to solve, I don't know if this is in the works as of yet (@Mabula-admin).


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(@sharkmelley)
White Dwarf Customer
Joined: 2 years ago
Posts: 15
July 4, 2019 15:58  

Have you tried rotating your panels by 90 degrees (to create a horizontal Milky Way) and using "Calibrated Projective"?

https://www.astropixelprocessor.com/community/main-forum/distorted-milky-way-mosaic/#post-1389

Rotating the panels before loading them into APP was a crucial step - no other combination worked.

Mark

This post was modified 5 months ago by Mark Shelley

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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
July 10, 2019 11:49  
Posted by: Mark Shelley

Have you tried rotating your panels by 90 degrees (to create a horizontal Milky Way) and using "Calibrated Projective"?

https://www.astropixelprocessor.com/community/main-forum/distorted-milky-way-mosaic/#post-1389

Rotating the panels before loading them into APP was a crucial step - no other combination worked.

Mark

Hi Mark, yes, tried this as well. 

I talked to Wei-Hao Wang about this a while ago when I asked him how he did his great 360 degree milkyway (his answer was sincere and long, well done manual work!) and he had suggested to Mabula before to implement a 360 degree projection, like PTGUI and many others have. 

Cannot think of another way

Regards,

Stefan


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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
July 17, 2019 09:18  

one month by now, too bad, still now answer


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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
December 9, 2019 11:15  

Hello,

so, meanwhile half a year has gone by. New version 1.075 and after some hours of trying and failing I would like a recommended approach of the above problem

_

Stefan


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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
December 9, 2019 13:38  

so, after another 2 1/2 hours always getting this: 

2019 12 09 12 51 10 Greenshot

I wait for some hints.

Ptgui finds the paramters at once without help. Older versions of it need help in form of giving the program socalled control points. Then it works right away.

How can I get the milkyway mosaic like this

2019 06 13 16 39 34 Greenshot

 

with APP?

_

stefan


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(@vincent-mod)
Quasar Moderator
Joined: 2 years ago
Posts: 1040
December 9, 2019 14:58  

Hi Stefan,

So sorry for missing this one, it was a bit of a chaotic period in the time you asked your question. I'll make sure Mabula knows about this and hopefully you get an answer asap! @mabula-admin


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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
December 10, 2019 12:55  

I reread all I could find and saw Mark's suggestion on turning the images again and that solved it. Actually crazy after trying every other combination before and failing. Maybe this should be implemented. Turning stacks can be a pain in APP, especially with larger files. Due to the time passed I forgot this possibillity, partially relieved partielly annoyed though... Does APP use swap files? Sometimes it does not work with their own created (big mosaic) files or is really slow. In Pixinsight these things are a lot faster


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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
December 10, 2019 13:36  

2019 12 10 13 31 58 Greenshot

not so good result. milkyway is curved, LNC needs to be a lot better (2nd & 3it)


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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
December 10, 2019 13:49  

St med 29557.0s NR x 1.0 LZ3 NS full eq add sc BWMV adv AAD EQ MBB20 2ndLNC it3 small

this is how it looks like stretched and saturated, very uneven.

would it be better to do the bigger efford to subtract LP on each panel before doing the mosaic? So far I have never done this. Or increase LNC and maybe MBB and do LP & starcolor on the final mosaic? How to get rid of the curved milkyway?


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(@vincent-mod)
Quasar Moderator
Joined: 2 years ago
Posts: 1040
December 10, 2019 13:54  

Ok, so yes this should be improved and I know Mabula has it on his list, but it's unknown to me what the status of that would be. Personally I have had better success with getting each panel really processed nicely and indeed doing the LP etc. APP is not yet fully optimized for this field of view I think, but given what you have now it should work. I am curious though as to why the differences are so big, I'll ask Mabula that as well.

This post was modified 3 days ago by Vincent Groenewold - Moderator

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(@elgol)
Main Sequence Star Customer
Joined: 2 years ago
Posts: 41
December 11, 2019 12:14  

Hi Vincent,

I checked the files and I see no reason why there is such a break in colors. Settings etc are the same. I tried a downscaled to 0.1 version with LNC 4th 6it and did some quick LP:

2019 12 11 12 07 25 Greenshot

Looks like it's gonna be processing each panel, which I wanted to avoid. Not only because of time consumption but also because of possible different  errors between them. I will see.

Where is Mabula?

Stefan


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