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First time mosaic question

Astrophotography DSO
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#1 ParagPA

ParagPA

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Posted 05 October 2022 - 10:15 AM

Hello,

 

I'm going to attempt my first mosaic tonight (I assume that's considered an advanced topic - sorry if this belongs in beginner). 

 

I'm going to do the veil complex, and I've got an ED80-T (480mm focal dist) and CEM40 mount. Tonight is a trial run, so I'm just going to grab an hour of each panel. My plan is to do a 4-panel mosaic, which given the FOV of the ED80-T and size of veil, will give me a substantial amount of surrounding area. My specific questions:

 

1) How much overlap should I plan between the panels? 

2) I'm using an L-extreme, so LP should be mitigated - but there will still be decent moonlight tonight. Will I run into trouble with correcting gradients between panels  if I grab each panel in sequence? I suppose best case would be to alternate between each panel, but that would seem to eat up a lot of imaging time. What's best practice? 

 

Any other early "gotchas" I should know about would be appreciated. Thanks very much for the advice!

 

If it matters I'll be using NINA to plan and grab the panels, and I typically work in PixInsight. 



#2 Rasfahan

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Posted 05 October 2022 - 10:36 AM

I've just reprocessed two of my mosaics with a different workflow. Before, I used APP which gave good to decent results. The rework in Pixinsight was a lot more work but also a lot better. So, here's my answers:

 

1) 15% overlap. If you have image rotation over the night, dither a lot, need to crop because of aberrations or vignette, you need to subtract that, of course. 10% would be the bare minimum in my book.

2) In Pixinsight, the workflow is

DBE

Color Calibration

MosaicByCoordinates

SplitMosaicTiles+PhotometricMosaic or GradientMergeMosaic (these join the frames - the first one worked better for me)

DBE

Then proceed from linear as normal.

 

So you remove the gradients as best you can beforehand, then join with a process that merges the gradients, then do more gradient removal. I gathered 1h of each panel before switching to the next (basically switching when I would refocus anyway). The first DBE step is critical, you need to take well care of that.

 

Here's my result with this workflow, it also contains the old revision what I got when I tried it with APP:

get.jpg?insecure


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#3 Raginar

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Posted 05 October 2022 - 11:13 AM

Agree with the above.  

 

Video I'd use to stitch them together:

https://www.youtube....h?v=urcTP3IMg1I

 

Good luck, it's significantly easier to do mosaics today than it was 5 years ago.

 

 

 

Hello,

 

I'm going to attempt my first mosaic tonight (I assume that's considered an advanced topic - sorry if this belongs in beginner). 

 

I'm going to do the veil complex, and I've got an ED80-T (480mm focal dist) and CEM40 mount. Tonight is a trial run, so I'm just going to grab an hour of each panel. My plan is to do a 4-panel mosaic, which given the FOV of the ED80-T and size of veil, will give me a substantial amount of surrounding area. My specific questions:

 

1) How much overlap should I plan between the panels? 

2) I'm using an L-extreme, so LP should be mitigated - but there will still be decent moonlight tonight. Will I run into trouble with correcting gradients between panels  if I grab each panel in sequence? I suppose best case would be to alternate between each panel, but that would seem to eat up a lot of imaging time. What's best practice? 

 

Any other early "gotchas" I should know about would be appreciated. Thanks very much for the advice!

 

If it matters I'll be using NINA to plan and grab the panels, and I typically work in PixInsight. 


  • ParagPA likes this

#4 ParagPA

ParagPA

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Posted 05 October 2022 - 11:46 AM

I've just reprocessed two of my mosaics with a different workflow. Before, I used APP which gave good to decent results. The rework in Pixinsight was a lot more work but also a lot better. So, here's my answers:

 

1) 15% overlap. If you have image rotation over the night, dither a lot, need to crop because of aberrations or vignette, you need to subtract that, of course. 10% would be the bare minimum in my book.

2) In Pixinsight, the workflow is

DBE

Color Calibration

MosaicByCoordinates

SplitMosaicTiles+PhotometricMosaic or GradientMergeMosaic (these join the frames - the first one worked better for me)

DBE

Then proceed from linear as normal.

 

So you remove the gradients as best you can beforehand, then join with a process that merges the gradients, then do more gradient removal. I gathered 1h of each panel before switching to the next (basically switching when I would refocus anyway). The first DBE step is critical, you need to take well care of that.

 

Here's my result with this workflow, it also contains the old revision what I got when I tried it with APP:

get.jpg?insecure

This is very helpful - thank you!




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