Astrophotography - Stacking Pictures with Different Exposure Lengths (Astro-HDR)

[ueberbelichtetesfoto]

Let's say you have some astrophotos, but with different exposure times.

Such as

• 4 pictures with 900s each
• 15 pictures with 240s each
• 60 pictures with 60s each
• a proper set of calibration frames for each exposure length.

This gives about an hour at each exposure level, but some pictures will have bright nebulas with stars burned out, and others won't.

 

What is the recommended way of stacking these into a single image?

Can I just add all of them into the same file group and Affinity Photo will figure out that these belong to different exposure lengths?

Or should I use the file group feature for this?

Another idea that came to mind is to first create three different images using the Astrophotography Stack Persona, i.e. one image for each exposure length, together with the corresponding calibration frames. Then use these images without Level and Curve Adjustments, and add them to the HDR persona, where Affinity Photo should be able to figure out that this is basically an HDR with 3 pictures at exposure levels -2, 0 and 2.

I don't have the pictures yet, as I wanted to ask first before wasting my time in case Affinity Photo isn't able to combine these properly.

 

Or is the general idea of an Astro-HDR already a bad idea in itself?

Best regards

[DWright]

Hi @ueberbelichtetesfoto,

Welcome to the forum 

Is it possible for a copy of your astrophotos using the Dropbox link below so I can test to see if there is a best method of combining these photos.

https://www.dropbox.com/request/WVE0VjgkG9cH6TaTP3ip

[ueberbelichtetesfoto]

Hi @DWright

 

I haven't done the pictures yet, as I wanted to ask first.

Once the clouds go away, I'll simply take some pictures with the exposure lengths listed above and will report back. So this could take a while.

[cebye]

I am also interested in how to use Affinity Photo stacking to combine different exposure times. Recently, I imaged M31 at 10, 60, and 600 seconds.

I'd be happy to provide sample files (light, dark, flat, bias) with multiple exposure times for testing. May I use the same Dropbox link provided, or will you provide a new one for me?

[ueberbelichtetesfoto]

Hi @cebye

I'm still waiting for a clear sky here.

I think one has to mention @DWright in the comment, so they get an email.

[cebye]

@DWright,

I am also interested in how to use Affinity Photo stacking to combine different exposure times. Recently, I imaged M31 at 10, 60, and 600 seconds.

I'd be happy to provide sample files (light, dark, flat, bias) with multiple exposure times for testing. May I use the same Dropbox link provided, or will you provide a new one for me?

Thank you, @ueberbelichtetesfoto

 

[cebye]

I'll try a new reply, copying a link to @DWright...

I am also interested in how to use Affinity Photo stacking to combine different exposure times. Recently, I imaged M31 at 10, 60, and 600 seconds.

I'd be happy to provide sample files (light, dark, flat, bias) with multiple exposure times for testing. May I use the same Dropbox link provided, or will you provide a new one for me?