R G and B images out of alignment

[irtuk]

Hey folks.

I made the jump last week to a ZWO mono camera and filter wheel setup and I am quite pleased with the new, cliff like learning curve ahead of me, however I am now looking for some suggestions on how to align the stacked images.

Searching these forums there are a couple of threads on it but nothing conclusive so far.

I have installed Siril ( not a clue what's going on there ) and the ZWO ASI software ( seems pretty basic ) but neither of these packages has enabled me to line up the R, G and B channels to get into photoshop.

The three stacked TIFF's are attached, you can see that they are not lining up correctly, I did 60 Red, then 60 green, then 60 blue, so,  as this is unguided, there's some drift in the images.

So, 

 

1. What software options are there to align these three images and keep them separate, obviously I can stack them in DSS but that then means I can't get to the colour information?

2. Why is the green channel so much brighter than the other two?

Blue.tif Green.tif Red.tif

[ollypenrice]

The mono learning curve should be a half inch curb, not a cliff! 

I do all my stacking and calibrating in AstroArt which also has an image alignment tool. I'm sure any astro-specific stacking/calibrating software will have the same facility. I don't know Siril but I think it must have it. Maybe try a question mentioning it specifically?

Olly

[knobby]

Stack the RGB separately in DSS but on the first colour ( any one ) choose the best frame and right click it then select use as reference.

Probably something similar in Siril.

Easiest way I've found to combine the images afterwards is to open all 3 in Photoshop then in channels choose combine and select the correct colour for each channel.

Our own @carastro has a link on her website that shows this nicely.

https://youtu.be/Qz3JVSZb90Q

Edited April 18, 2021 by knobby

[irtuk]

ok so if I am interpreting this right, I am stacking all the red channel images and picking my best red frame ( for sake of argument ) and using that as a reference frame, then stacking all my blue channel images but with the one single red frame checked and set to reference, then repeat that with green channel to get three separate images, R, G and B channels that are aligned to the reference.

That's what I am trying now

 

[irtuk]

it looks like, possibly, I don't need to check the reference frame, it keeps that little "I am a reference frame" asterisk when unchecked but I will see.....

 

After work.....

[wimvb]

In any stacking software you should be able to select a reference image that is not going into the stack. If you can’t do that, it’s time to consider another stacking program.