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INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

Re:How to shoot comets?

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How to shoot/track comets properly with kstars/ekos?
How to process afterwards? I use DSS or APP.
Any advise?
Thanks!
-- Max S
ZWO AM5. RST-135. AZ-GTI. HEQ5. iOptron SkyTracker.
TPO RC6. FRA400. Rokinon 135 and other lenses.
ZWO ASI2600MC. D5500 modified with UVIR clip-in filter.
ZWO ASI120MM Mini x 2. ZWO 30F4 guider. Orion 50mm guider.
ZWO EAF x 2.
Last edit: 3 years 11 months ago by maxthebuilder.
3 years 11 months ago #51504

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Replied by Eric on topic Re:How to shoot comets?

Exposure duration depends on your guider, and the speed of the comet. For comet Atlas C/2019 Y4, the speed is about 1 arcmin per minute, probably more, so check how many pixels that result in if you guide on stars. Guiding on comet directly is supported by phd2, but it's tricky and manual.

If you decide you can capture with star-based guiding, you can use the scheduler to add capture jobs. Run enough captures so that the comet doesn't evade your field of view, then duplicate the observation jobs so that Ekos recenters the comet periodically.

Oh and don't forget to update comet orbital information in kstars before that.

Processing in DSS is fairly easy, as DSS can locate the comet core in each frame and stack accordingly.

-Eric
3 years 11 months ago #51505

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Replied by PDB on topic Re:How to shoot comets?

"Guiding on comet directly is supported by phd2, but it's tricky and manual"

from CdC you can send the comet guiding parameters directly to Phd2

Paul
3 years 11 months ago #51507

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Thanks!
Will try tonight using your suggestions.
-- Max S
ZWO AM5. RST-135. AZ-GTI. HEQ5. iOptron SkyTracker.
TPO RC6. FRA400. Rokinon 135 and other lenses.
ZWO ASI2600MC. D5500 modified with UVIR clip-in filter.
ZWO ASI120MM Mini x 2. ZWO 30F4 guider. Orion 50mm guider.
ZWO EAF x 2.
Last edit: 3 years 11 months ago by maxthebuilder.
3 years 11 months ago #51523

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Replied by maxthebuilder on topic How to shoot comets?

Oh... I was completely unaware of the "Edit Comet Mode" in DSS. Now I am.
That's something I was missing (I was wrongly assuming that DSS would auto-detect a comet)
-- Max S
ZWO AM5. RST-135. AZ-GTI. HEQ5. iOptron SkyTracker.
TPO RC6. FRA400. Rokinon 135 and other lenses.
ZWO ASI2600MC. D5500 modified with UVIR clip-in filter.
ZWO ASI120MM Mini x 2. ZWO 30F4 guider. Orion 50mm guider.
ZWO EAF x 2.
3 years 11 months ago #51530

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Replied by David James on topic How to shoot comets?

If you had a big enough guidescope, could you guide directly on the comet with KStars?

The processing program Siril can also deal with stacking frames containing a comet, though it helps to already be familiar with Siril as it has a bit of a learning curve (helps if you can read French, too).
Last edit: 3 years 11 months ago by David James.
3 years 11 months ago #51534

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Replied by maxthebuilder on topic How to shoot comets?

I don't even see the comet on my guide camera...
Well. Shooting it right now. C/2019 Y4 ATLAS.
AT72ED with ATI294MC. 120 sec exposure, Gain 200. Guiding on stars. Internal guider.
The comet looks pretty small with my setup.
-- Max S
ZWO AM5. RST-135. AZ-GTI. HEQ5. iOptron SkyTracker.
TPO RC6. FRA400. Rokinon 135 and other lenses.
ZWO ASI2600MC. D5500 modified with UVIR clip-in filter.
ZWO ASI120MM Mini x 2. ZWO 30F4 guider. Orion 50mm guider.
ZWO EAF x 2.
3 years 11 months ago #51538

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Replied by Eric on topic Re:Re:How to shoot comets?


Agreed. KStars/Ekos doesn't have that feature. However, once the rates are sent, it still requires the mount to have good polar alignment and low periodic error. So that makes use of tricky prerequisites.

PHD2 also has a "comet training mode", which requires those guiding parameters, and around ten minutes of manual guiding to refine those for your own setup.

Note that none of this is "guiding on the comet" unfortunately. That's already quite cool!

-Eric
3 years 11 months ago #51539

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Replied by Eric on topic Re:How to shoot comets?


You're supposed to look for the coma :) it is expected to be around 12-15 arcmin currently, which your telescope can certainly handle. Leave the core for higher focal lengths.

-Eric
3 years 11 months ago #51540

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It's certainly visible. I am on the 40th frame right now..
The comet is close to a bright street light unfortunately. Getting terrible flares. I have limited viewing angles in my front yard : (
-- Max S
ZWO AM5. RST-135. AZ-GTI. HEQ5. iOptron SkyTracker.
TPO RC6. FRA400. Rokinon 135 and other lenses.
ZWO ASI2600MC. D5500 modified with UVIR clip-in filter.
ZWO ASI120MM Mini x 2. ZWO 30F4 guider. Orion 50mm guider.
ZWO EAF x 2.
3 years 11 months ago #51542

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Replied by maxthebuilder on topic How to shoot comets?

Is there any other software other than DSS and Siri to stack comet sequences? PI, I guess... (but I am not getting there).
I am still to try Siril.
DSS sort of works.
In 'comet only" mode it produces some strange artifacts.
In "comet and stars" mode the result looks better at first look but the background looks weird and the color is missing...
Maybe all this is just because my dataset is not very good.
-- Max S
ZWO AM5. RST-135. AZ-GTI. HEQ5. iOptron SkyTracker.
TPO RC6. FRA400. Rokinon 135 and other lenses.
ZWO ASI2600MC. D5500 modified with UVIR clip-in filter.
ZWO ASI120MM Mini x 2. ZWO 30F4 guider. Orion 50mm guider.
ZWO EAF x 2.
Last edit: 3 years 11 months ago by maxthebuilder.
3 years 11 months ago #51543

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Replied by Eric on topic Re:How to shoot comets?

Keep trying, it should work. My version of DSS can't handle the mode putting both comet and stars stacked, but the two others are working for me.

PI is not easy at all with comets (my own experience). However, you can batch-process your subs for noise and contrast and create a time-lapse, which is equally cool.

-Eric
3 years 11 months ago #51599

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