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Speaking of which...
Here's Comet C/2022 E3 (ZTF), taken Friday morning (2023-01-27) from my back patio.
I've mentioned before that astrophotography is an exercise in failure. A celebration of failure! An onion of failure that you have to peel one layer at a time, with each peel revealing yet another layer of failure. It's OK though, as long as I learn a little along the way. Needless to say, the above image wasn't my first attempt (fourth?, fifth?). I could seriously go on and on about this one. I'm beat. Sooo much "learning."
Processing comets is a real challenge, since they move quite quickly against the background stars. Ya have to get quite clever in stacking techniques to avoid streaking in the stars and/or the comet itself.
Equipment:
Sky-Watcher EQ6-R Pro mount
Explore Scientific ED80-FCD100 telescope
Astronomik RGB filters
Orion Field Flattener for Short Refractors
ZWO ASI1600MM-Pro monochrome camera
Guide scope and ASI290MM-mini guide camera
Software:
N.I.N.A.
PHD2
PixInsight
Integration:
Bortle class 7 (maybe 8 ) skies
R: 57×40 sec
G: 57×40 sec
B: 57×40 sec
Subframes were acquired in a loop, alternating R, G, B, R, G, B..., and so on (this is important for later). Telescope tracking/guiding was done on the background stars (like normal). Total integration/exposure time: 1.9 hours. I would have acquired for longer but there was a fixed window from the time the comet rose above my building till morning twilight. I even moved my telescope to a part of the patio that makes no sense except for the comet (at the expense of most everything else. There's a whole story there).
Two phases of stacking/alignment were performed. Phase 1 is aligning on the background stars. When integrating that stack, heavy emphasis was placed on Winsorized Sigma Clipping for high valued pixels: The idea was the comet streak would be treated as a statistical anomaly, leaving pretty much only the background stars.
For phase 2, frames were aligned on the comet (same raw data on the previous phase, just aligned differently). But before alignment on the comet, the background stars (from the previous step) were subtracted from each frame, leaving pretty much only the comet after integrating that stack.
Finally, the stacked image of the stars were combined with the stacked image of the comet. Lots of other miscellaneous processing steps were performed, not mentioned here.
----
I have a slightly different configuration set up now as I write this. Hopefully I'll be able to get a wider field of view with it. Weather's looking iffy though. Clouds are coming in. Sooo much learrrning.
[Edit: clouds came in. No additional "learning" attempt for me today. I'm going to go munch on an onion.]
Here's Comet C/2022 E3 (ZTF), taken Friday morning (2023-01-27) from my back patio.
I've mentioned before that astrophotography is an exercise in failure. A celebration of failure! An onion of failure that you have to peel one layer at a time, with each peel revealing yet another layer of failure. It's OK though, as long as I learn a little along the way. Needless to say, the above image wasn't my first attempt (fourth?, fifth?). I could seriously go on and on about this one. I'm beat. Sooo much "learning."
Processing comets is a real challenge, since they move quite quickly against the background stars. Ya have to get quite clever in stacking techniques to avoid streaking in the stars and/or the comet itself.
Equipment:
Sky-Watcher EQ6-R Pro mount
Explore Scientific ED80-FCD100 telescope
Astronomik RGB filters
Orion Field Flattener for Short Refractors
ZWO ASI1600MM-Pro monochrome camera
Guide scope and ASI290MM-mini guide camera
Software:
N.I.N.A.
PHD2
PixInsight
Integration:
Bortle class 7 (maybe 8 ) skies
R: 57×40 sec
G: 57×40 sec
B: 57×40 sec
Subframes were acquired in a loop, alternating R, G, B, R, G, B..., and so on (this is important for later). Telescope tracking/guiding was done on the background stars (like normal). Total integration/exposure time: 1.9 hours. I would have acquired for longer but there was a fixed window from the time the comet rose above my building till morning twilight. I even moved my telescope to a part of the patio that makes no sense except for the comet (at the expense of most everything else. There's a whole story there).
Two phases of stacking/alignment were performed. Phase 1 is aligning on the background stars. When integrating that stack, heavy emphasis was placed on Winsorized Sigma Clipping for high valued pixels: The idea was the comet streak would be treated as a statistical anomaly, leaving pretty much only the background stars.
For phase 2, frames were aligned on the comet (same raw data on the previous phase, just aligned differently). But before alignment on the comet, the background stars (from the previous step) were subtracted from each frame, leaving pretty much only the comet after integrating that stack.
Finally, the stacked image of the stars were combined with the stacked image of the comet. Lots of other miscellaneous processing steps were performed, not mentioned here.
----
I have a slightly different configuration set up now as I write this. Hopefully I'll be able to get a wider field of view with it. Weather's looking iffy though. Clouds are coming in. Sooo much learrrning.
[Edit: clouds came in. No additional "learning" attempt for me today. I'm going to go munch on an onion.]
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