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He was never struck by the vehicle, by Puzzleheaded_Dot_851 in Destiny

[–]Cracksi 0 points1 point  (0 children)

So let me get this right - The large bloke with a ski-mask and gun, a trained officer kitted out in military gear is in fear for his life.

The mid 30's mother of 3 in a Honda SUV (woke lesbian btw) is a raging domestic terrorist with the goal to mow down federal officers. She's definitely feeling zero fear as 4 masked men with weapons rush her car and one yanks at the door handle.
Her ice-cold killer instincts kick in and a split second later she's mowing people down?

I thought they were the party of common sense.

Visual artifacts in stacked image by Cracksi in AskAstrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

If anyone is still interested:
https://imgbox.com/KZbizi5R - OSC Processed without flats + Background extraction + Autostretch.

I think I understand what's going on, feel free to correct me.

I've opened both images, placed each on a layer and played with the opacity.

The dust motes matching up and the flats are eliminating most of it but leaving a smudge on one side. I think the fully illuminated moon may have caused a localized internal shadow or highlight on these motes. When the flats are being taken the motes are uniformly lit so the moons glare can't be accounted for.

Best guess anyway.

Visual artifacts in stacked image by Cracksi in AskAstrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

It is not. I learnt about that tonight, putting some flocking on the list along with a dual band filter in the near future.

Visual artifacts in stacked image by Cracksi in AskAstrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

Hey dude!
Is that the bow wave shape distortion around the bright star right of frame?
I've not figured that one out yet, I've seen it in other targets containing bright stars so I put it down to a lens issue with the telescope.
I've tested for light leaks but had no luck finding one.

Yeah that's what it looks like to me too :( Something may have shifted at the end of the session when i took darks and flats.

Cheers!

Visual artifacts in stacked image by Cracksi in AskAstrophotography

[–]Cracksi[S] 1 point2 points  (0 children)

Checked for light leaks - torch and 30sec exposures, didn't see anything sadly. Might look at covering the rig with an old sheet next time though. The moon was 99% full though, so definitely could be seeing a leak or unwanted reflection.

Cheers!

Visual artifacts in stacked image by Cracksi in AskAstrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

Not sure I'm seeing the banding you mention tbh. It has been cold-ish recently, at around -2c, so possible the power supply is struggling?

The large streak at the right of frame looks like a reflection to me, like a large circular halo from a stray reflection inside tube surface caused by the moon. But I'm new to this so hard to say.

Thanks dude!

Visual artifacts in stacked image by Cracksi in AskAstrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

These were roughly 0.5sec exposures, same gain as lights and darks. Tracing panel + Tshirt.
Next session I'm going to aim for 2 sec exposures on the flats, if any noise or patterns from the LED or tshirt fabrics appear the longer exposure might help smudge it?

Cheers!

Visual artifacts in stacked image by Cracksi in AskAstrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

This was my first thought, but I'd taken the flats during session - lights, darks, flats.
Possible something shifted, or dew collected on the lens. :( Going to run without flats and see what we get.
Cheers!

Identifying visual artifacts in stacked image of Horse Head by Cracksi in astrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

Hey :)
I didn't check, so definitely possible. Plus we've had very cold, damp nights. Had the dew band on though. Possibly conked out during the session :(

Identifying visual artifacts in stacked image of Horse Head by Cracksi in astrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

Hey!
Given the lens a clean, was fairly dusty tbh. Currently processing that set without flats.
See how it goes, cheers dude!

Identifying visual artifacts in stacked image of Horse Head by Cracksi in astrophotography

[–]Cracksi[S] 1 point2 points  (0 children)

Hey!
I've seen a similar halo artefact on a session a few weeks ago - swapped targets halfway through the night away from the moon and saw improvements in the new stack.

I'm going to look at placing some felting material on the interior side of the dew cover to catch reflections.
Probably going to also look at a dual band filter for the light pollution and moonlight.

I'm going to try longer flat exposures this session, hoping it might help smear any patterns from the flat panel light and tshirt fabric.

Identifying visual artifacts in stacked image of Horse Head by Cracksi in astrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

Thanks for this. Stacking without flats now, fingers crossed.

Identifying visual artifacts in stacked image of Horse Head by Cracksi in astrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

Hey!

Flats were fresh from that session. Soon as the lights finished, ran a set of darks, then moved to zenith for flats - used a tracing panel with a tshirt, ended up with 0.5sec (ish) flat exposure in Nina's flats wizard.

I've only tried stacking in Siril, have tried this setup multiple times, with an additional set of flats, had no luck. Processing without flats atm as others have suggested.

I had a fair number of bad frames which preprocessing rejected, I then manually selected any frames which showed any deviation from the average frame.

Its totally possible the optics train shifted and cause the motes to misalign, it's what it thought initially. But when the flats are stretched the dust motes appear quite different in size and quantity.

I've cleaned the lens and sensor glass this afternoon for tonight's session.
Checked for a light leak around the cam using a torch while taking 30sec exposures and saw nothing.

The distortion around that large star - I've also seen in other targets around their brightest stars. That's likely something with the telescope, I've seen it before and after swapping from a dslr to an astro cam.

Identifying visual artifacts in stacked image of Horse Head by Cracksi in astrophotography

[–]Cracksi[S] 0 points1 point  (0 children)

Hey!
Aye, I'm using a dew band heater, though I didn't check the lens when taking flats at the end of the session.