HDR processing without different exposure lengths

[Icesheet]

I'm wondering if there is a way of doing a form of HDR processing without data of different exposure lengths? I captured some widefield M81/ 82 data with 5min exposures to bring out the IFN. I've managed to do this, however, no matter what I do I can't bring out the IFN without completely blowing the galaxies out. I've tried everything from masking to layers but can't achieve anything with any detail in the galaxies without artifacts around them. Can anyone point me to a good tutorial? I mainly use PixInsight but have Photoshop too. Happy to make the data available if anyone wants it too. Forgive the corner stars though!

 

Edited April 5, 2023 by Icesheet

[Fegato]

I took a big widefield image of this area in February. It is hard to keep the galaxies down. With some advice from others, I used the Gain script to produce a mask for the galaxies.  They still ended up fairly bright, but I was reasonably happy with them in the end. 

 

I have used HDRMultiScaleTransform without using HDRComposition and multiple exposure lengths, and sometimes it works OK for me. I tried it with this one, but couldn't find a setting that didn't give me nasty artifacts, so I gave up with it. 

[Icesheet]

Thanks! I haven’t tried the Gain script or HDRMultiScaleTransform so I’ll give them a go. I managed to get something a bit more like what I was hoping for by really pushing the IFN in one layer and lightly stretching the  galaxies in another layer in Photoshop then set the top IFN layer at 60% opacity. A bit too much colour mottling for my like though. 

Edit to add: I just had a look at your fantastic version @Fegato. So much detail in the IFN and galaxies very well controlled. I would delighted with that!

Edited April 6, 2023 by Icesheet

[Fegato]

Thanks! I did have all sorts of trouble with it - I think bright galaxies and faint IFN is a particular challenge!