How to process my Saturn image through RGB align to reduce color fringing?

[lcd1080 (Peter)]

Clayton helped me with one of my earlier Saturn images by processing it through RGB align in Registax to reduce the color fringing caused by imaging at a low 27 degree planetary elevation. I have a more recent Saturn image with even worse color fringing issues (see below). Can anyone tell me how to open a single BMP file in Registax to do this without having to re-process the entire AVI file? I thought that Registax would only accept AVI movie files so there's obviously a gap in my understanding.

Thanks Peter

Originally Posted by Clayton

Not a bad shot Peter.
I hope you don't mind me taking the liberty of running your pic through RGB align in Registax to reduce the colour fringing.

[Clayton]

Hi Peter,
When you go to the select button to select your AVI, at the bottom on the window there is a dropdown list which will allow you to select the file type you want (see pic.). I believe you can also "Drag and Drop" files from explorer into the Registax window (just tried it and it seems to work OK)
Bear in mind that atmospheric dispersion (AD) is a continuous dispersion like a rainbow and not discrete shifts for Red, Green, and Blue, so a RGB align may improve the picture but won't completely remove all evidence of the AD.
The worse the AD is the less that RGB align can help. You can buy an AD corrector which is an adjustable prism, but they are expensive and in my opinion unless you desperately wish to keep imaging through all the crud at low elevations, are probably not worth the investment.
Hope this helps

[lcd1080 (Peter)]

That worked fine, thank you very much Clayton! Learning that RGB align can't compensate completely for atmospheric dispersion helps me a lot too. I determined that AD has affected the blue component of my Saturn image to such an extent that it can't be fixed with RGB align. I found an AD corrector for about 550 US dollars (500 Australian) so that is pretty steep however I still might consider it since my "observatory" is my condo balcony which limits all observations to less than 39 degrees elevation. Thanks again!

Peter