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Star color

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gardenfish

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Location: Phoenix Az.

Post Fri Jan 20, 2017 6:05 pm

Star color

Looking at the stars close up the colors are different on both sides. On my HSO when I line up the rgb channels in the center of the picture the stars on the left show blue sticking out at 7 oclock and green at 2 oclock. On the right side the blue is at 5 oclock and the green is sticking out at 11 oclock. I hope you understand what I mean.

Is this from field curvature? If I adjust the spacing of the ff/fr would this correct this?

Thanks Rick
Takahashi TSA120
Takahashi TOA150
SV70T
CEM60 - PierTech2 pier
QSI6120 WSG-8
Astrodon 31mm LRGB E Series -Ha-3nm - OIII-3nm - SII-3nm

G3 Mono - ASI290MM Mini - ST80

ES 152 AR - Atlas mount
16" goto Dob

Nikon D5200 Modded

Roll-off roof Observatory
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Doug

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The good thing about science is that it’s true whether or not you believe in it. ― Neil deGrasse Tyson

Posts: 6416

Joined: Tue Dec 23, 2008 11:41 am

Location: Temecula, California

Post Fri Jan 20, 2017 6:09 pm

Re: Star color

Can you post an image showing what you mean?
Image
MyAstroImages.com Photo Album. Sharing Your AstroImages On Line!
More Images.
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CPC800, 60MM Classic Refractor, EON72, EON120, Atlas EQ-G, SSPro V1, SSAG, IDAS LPS Filter, TRF-2008
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gardenfish

Kiloparsec

Posts: 1082

Joined: Fri Feb 05, 2016 9:18 am

Location: Phoenix Az.

Post Fri Jan 20, 2017 6:25 pm

Re: Star color

I think you can see it here.


hso.jpg
hso.jpg (147.81 KiB) Viewed 5177 times
Takahashi TSA120
Takahashi TOA150
SV70T
CEM60 - PierTech2 pier
QSI6120 WSG-8
Astrodon 31mm LRGB E Series -Ha-3nm - OIII-3nm - SII-3nm

G3 Mono - ASI290MM Mini - ST80

ES 152 AR - Atlas mount
16" goto Dob

Nikon D5200 Modded

Roll-off roof Observatory
<<

gardenfish

Kiloparsec

Posts: 1082

Joined: Fri Feb 05, 2016 9:18 am

Location: Phoenix Az.

Post Fri Jan 20, 2017 6:27 pm

Re: Star color

I you look lower right and then on the left the green and blue are on different sides of star center.
Takahashi TSA120
Takahashi TOA150
SV70T
CEM60 - PierTech2 pier
QSI6120 WSG-8
Astrodon 31mm LRGB E Series -Ha-3nm - OIII-3nm - SII-3nm

G3 Mono - ASI290MM Mini - ST80

ES 152 AR - Atlas mount
16" goto Dob

Nikon D5200 Modded

Roll-off roof Observatory
<<

Doug

User avatar

The good thing about science is that it’s true whether or not you believe in it. ― Neil deGrasse Tyson

Posts: 6416

Joined: Tue Dec 23, 2008 11:41 am

Location: Temecula, California

Post Fri Jan 20, 2017 7:23 pm

Re: Star color

How are you aligning your stacked frames?

I'm wondering if alignment is the issue.
Image
MyAstroImages.com Photo Album. Sharing Your AstroImages On Line!
More Images.
:darkgrin:
CPC800, 60MM Classic Refractor, EON72, EON120, Atlas EQ-G, SSPro V1, SSAG, IDAS LPS Filter, TRF-2008
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DkN

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Giant Molecular Cloud (GMC)

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Joined: Mon Dec 30, 2013 3:17 pm

Location: Charlotte, NC

Post Fri Jan 20, 2017 9:10 pm

Re: Star color

Are you shooting OSC or mono? If mono, then is this LRGB or NB? The error is radial. If mono, did you refocus between filter changes?
Jeff

SV80ST w/ Moonlite CFL
GSO6RC w/ Moonlite CSL
ATIK 460EX mono Starlight Xpress Lodestar SX OAG & FW
Astronomik LRGB +Ha 12nm OIII 12nm SII 12nm IDAS LPS P2
SGP, EQMOD, PI, PS
Boxes of DIY
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gardenfish

Kiloparsec

Posts: 1082

Joined: Fri Feb 05, 2016 9:18 am

Location: Phoenix Az.

Post Sat Jan 21, 2017 5:05 am

Re: Star color

This is HSO with the Atik460. I never combined NB before so I aligned in rgb channels in ps as I know how to do that.. Probably not the correct way to combine nb but thought I would try it. When first put into the r-g-b channels it looks like a 3d picture without the glasses. when I align the channels to colors in the middle stars the edge stars are still misaligned and oppositely.

I did not focus between filters. When I set up I focused with the baht mask on Capella with the Ha filter. Then out of curiousity I switched to the OIII and the SII and without moving the focuser and still using the baht mask the focus was the same. These were the Orion 1.25 nb set that they claim parfocal. I have seen lots of revies of users and some say theirs are and some not. I am waiting on shipment of the 2" Astronomc NB's 6nm and am trying these until I get them.
Takahashi TSA120
Takahashi TOA150
SV70T
CEM60 - PierTech2 pier
QSI6120 WSG-8
Astrodon 31mm LRGB E Series -Ha-3nm - OIII-3nm - SII-3nm

G3 Mono - ASI290MM Mini - ST80

ES 152 AR - Atlas mount
16" goto Dob

Nikon D5200 Modded

Roll-off roof Observatory
<<

Doug

User avatar

The good thing about science is that it’s true whether or not you believe in it. ― Neil deGrasse Tyson

Posts: 6416

Joined: Tue Dec 23, 2008 11:41 am

Location: Temecula, California

Post Sat Jan 21, 2017 8:01 am

Re: Star color

I think you should try an alignment software. PS is hard to align correctly and it takes a lot of time in PS.

What astro software do you have now? I think you should try stacking each layer first (HA, L, R, G, B) then align the final stacks in an astro program of your choice. The little differences you're seeing could be that little tweak you can't seem to find when you're manually aligning in PS.
Image
MyAstroImages.com Photo Album. Sharing Your AstroImages On Line!
More Images.
:darkgrin:
CPC800, 60MM Classic Refractor, EON72, EON120, Atlas EQ-G, SSPro V1, SSAG, IDAS LPS Filter, TRF-2008
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cgome004

User avatar

Regular Satellite

Posts: 747

Joined: Fri Aug 28, 2015 11:43 am

Location: Navarre, FL

Post Sat Jan 21, 2017 1:40 pm

Re: Star color

Try using he star alignment in pixinsight. You can pick one as the reference and then input the others to match the alignment. You can also then make an rgb image in pixinsight with the channel tool. It is probably more accurate this way rather than trying to manually match everything. Also do all of this with the data unstretched and in linear form
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gardenfish

Kiloparsec

Posts: 1082

Joined: Fri Feb 05, 2016 9:18 am

Location: Phoenix Az.

Post Sat Jan 21, 2017 3:15 pm

Re: Star color

But the center stars are aligned good it is the outsides that are off. So would this be the ff. curvature? If I align the left stars the center and right are off. If I align the right the center and left are off.

I will try the PI alignment tomorrow during the rain showers.

Thanks Rick
Takahashi TSA120
Takahashi TOA150
SV70T
CEM60 - PierTech2 pier
QSI6120 WSG-8
Astrodon 31mm LRGB E Series -Ha-3nm - OIII-3nm - SII-3nm

G3 Mono - ASI290MM Mini - ST80

ES 152 AR - Atlas mount
16" goto Dob

Nikon D5200 Modded

Roll-off roof Observatory
<<

gardenfish

Kiloparsec

Posts: 1082

Joined: Fri Feb 05, 2016 9:18 am

Location: Phoenix Az.

Post Sun Jan 22, 2017 6:38 am

Re: Star color

I am aligning in DSS. These are combining the 3 subs I am talking about
Takahashi TSA120
Takahashi TOA150
SV70T
CEM60 - PierTech2 pier
QSI6120 WSG-8
Astrodon 31mm LRGB E Series -Ha-3nm - OIII-3nm - SII-3nm

G3 Mono - ASI290MM Mini - ST80

ES 152 AR - Atlas mount
16" goto Dob

Nikon D5200 Modded

Roll-off roof Observatory

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