15 replies to this topic

[Bob2023CL]

I don't know if this is the right place, so here goes.  Recently Mar was passing through M44 (Beehive).  I got a couple hours of data.  When I stacked the data I saw that Mars is moving.  Is there a trick for image processing a situation like this?  I was dithering as well, so getting Mars to hold still may be a challenge.  Just curious to see what people do with wandering objects.  Thanks.

[soojooko]

I don't know if this is the right place, so here goes.  Recently Mar was passing through M44 (Beehive).  I got a couple hours of data.  When I stacked the data I saw that Mars is moving.  Is there a trick for image processing a situation like this?  I was dithering as well, so getting Mars to hold still may be a challenge.  Just curious to see what people do with wandering objects.  Thanks.

Does it move a lot over the course of the session? I would have thought stacking would remove it seeing as its not in the same position across the subs.

[kathyastro]

You could try comet processing, where you get the software to stack the moving and stationary targets separately and then recombine them.  It can be tricky, but it is designed for exactly this situation.

[Bob2023CL]

Here is a simple stretch of the stack

 

[fishonkevin]

I had the same problem with Mars and the Pliedes a few years ago. All I did was process the 30 frame stacked picture like normal, Mars trailed. I got it so the Pliedes were nicely done, showing nebulosity. Then I did a slight process on a 10 frame stack. Mars stayed round. I then layered the upper left corner of the 10 frame stack onto the upper left corner of the 30 frame stack. Now I have a nice round Mars and a nebulous Pliedes. 

 

 

 

 

Edited by fishonkevin, 16 May 2025 - 07:36 AM.

[matt_astro_tx]

You could try comet processing, where you get the software to stack the moving and stationary targets separately and then recombine them. It can be tricky, but it is designed for exactly this situation.

Definitely worth trying this. That sounds like a cool shot. Worth experimenting with!

[soojooko]

I doesn't move much, so understandable that stacking would not know what to do with it.

 

If you want a simple solution, why not just crop the planet out? It looks like its far enough away from your target to not really matter too much. But if you want to keep the full frame, Kathys suggestion is probably the way to go.

[Andros246]

I don't know if this is the right place, so here goes. Recently Mar was passing through M44 (Beehive). I got a couple hours of data. When I stacked the data I saw that Mars is moving. Is there a trick for image processing a situation like this? I was dithering as well, so getting Mars to hold still may be a challenge. Just curious to see what people do with wandering objects. Thanks.

There will probably be minimal gain from stacking long exposure on a star cluster so it may not even be worth your time to try to solve your issue.

I would just stack a fraction of the data and see how it turns out.

[Bob2023CL]

I am not trying to get rid of Mars!  I was also wondering if there are planet stacking software where I could cheat and put it back later.  Does PixInsight have anything like that?  I have a nice shot of the Beehive and could make a mosaic with that HDTV look 

[soojooko]

I am not trying to get rid of Mars!

Apologies. I misunderstood! I thought you wanted to erase the planetary photobomb.

[Bob2023CL]

No Mars was the object of my affections that evening.  It was my last opportunity while it was close enough.  I have a small FOV

[Mike Phillips]

As a primary planet person it's technically not planet stacking, I think of lucky imaging when I hear that. I think Kathyastro has the best approach in that it's a small body that has non stellar motion needing compensation. I'm not offering solutions just my own clarifications.

Mike P in NC

[Bob2023CL]

Yes typically planet captures are very different than DSOs.  I've done the Moon and the Sun in the past using Sharpcap.  This is an unusual hybrid. 

[Alex McConahay]

Have you tried star removal? Does Mars go with the stars or with the background?

 

If it in fact separates,  then figure out how to register the Mars only frames such that they stack better. 

Alex

[smiller]

I shoot comets and asteroids passing deep sky targets as well as the motion of minor planets.  I think there are three ways I would consider approaching it:

 

1) As Kathy mentioned, try comet processing.

 

2) Another method is to simply stack your data in small bite-size chunks, such as five minute chunks.  Just make each small enough that the motion of Mars is small enough that whatever details you can realize in your exposures is not ruined in the stack.  This should also render the beehive cluster with reasonable fidelity because these are bright stars.

 

Now just register the sub stacks, and these are your animation frames which will render both the beehive cluster with reasonable fidelity and Mars without much motion.  You may want to sharpen the Mars in each of the images to bring out its features.

 

Here is an example where I did this with the crystal ball nebula and an asteroid passing nearby:

 

The crystal ball nebula was fairly bright so the substacks actually rendered the nebula with reasonable fidelity.  Also when you animate frames of deep sky objects, for some reason, the integration are brain makes with the object helps reduce noise because of the fact that it’s now a video.

 

 

3) The final method is creating a composite which I’ve also done where you stack all of the images registering on the stars and just ignore Mars for now. And then you do what I describe in step number two, create a bunch of substacks to animate Mars and manually remove Mars in your master image of the beehive cluster and for each animation frame put in the Mars from those frames into your master beehive image, so that you have Mars rendered with a small number of lights, but the beehive cluster is rendered with all of your lights so it’s more of a composite animation.

 

Here is an example where I did it with the jellyfish nebula, which is much dimmer than the Crystal Ball nebula and I wanted the entire stack for that but then I did a composite with an asteroid going in front with the asteroid animation frames.

 

Obviously asteroids are point sources and not like a planet, but I think the concept is similar.

Edited by smiller, 16 May 2025 - 10:23 AM.

[Bob2023CL]

I was thinking of that.  I had Flora photobomb my Leo Triplet recently.  These are good ideas.  I always loved to make movies.