Stacking images for sharp stars – Having trouble following tutorial

[JustMeJ]

Hey guys,

 

I’ve been trying to follow along with James’ tutorial on YouTube on how to get pin sharp stars. Unfortunately, I am already failing right after the import:

 

(macOS 10.13, Mac App Store version of Affinity Photo – my trial expired so I had to buy the app even though I wanted to test this first  )

 

1. I had my RAW images in Lightroom.

2. I exported them to a folder on my Desktop (.tif format).

3. I opened AP → File → New Stack.

4. I  selected all my 56 photos, which were taken over the course of 10 minutes.

 

If I select "Auto Align", I end up with one single layer at the end, and no stars. The trees are there, the castle is there, but no stars. It’s as if AP has "denoised" the sky and in the process removed the stars.

 

If I do not select Auto Align (just for kicks), it doesn’t matter if I pick mean or media for the group – no stars in the sky, either. If I select Outlier or anything else, I get star trails (which I don’t want). Of course, my individual layers in the group have the stars, but how do I get them to show up in the "Live Stack Group"?

 

I must be missing something super obvious – help?

[John Rostron]

The Auto Align is being faced with conflicting criteria. If it aligns the earthly trees and castle, then it cannot align the stars and vice-versa. The only thing I can suggest is that you blur the outline where the sky meets the earth, then your stars will be the only points that auto-align could work on. I would also suggest that you use the 'maximum' option on the stack to best show the stars.

You could then add the unblurred background back in at the end.

 

John

[JustMeJ]

Hey John,

 

Thanks so much for the explanation! You might be right: in James' video, there were only stars so the app didn't have to decide between foreground and sky, as is the case in my photo. I’m relieved, I already started to doubt my ability to click the same buttons as he did

 

I’ll play around with this a bit more, thanks for getting me on the right track!