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Some live captures using a small APO


RobertI
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Posted (edited)

First 'proper' EAA session in a long time. My goal was to try a new 'quick setup' wide field combination using:

  • My Skyprodigy mount (big question - would it be able to auto align, put the object on the chip, and accurately track for 10-20 seconds?)
  • Zenithstar 66mm @ F4.8 plus IR filter
  • Lodestar mono for capture (it's been producing strange artefacts, so might play up)
  • Jocular for live processing (new to me), Starlight Live for capture.

So there were lots of opportunity for failure, but I'm pleased to say it all worked flawlessly, so I now have a wide(ish) field EAA setup that can self-align and be ready for imaging in a few minutes. 

The Lodestar is not perfect for short focal length with its massive pixles, and the bright summer skies were not ideal, but I was pretty pleased with the results. Jocular was fantastic to use, the median stack doing a great job of removing hot pixels and other artefacts. Captures were either 10 or 20 seconds, except the glob which was around 5 secs I think.

 

 1259125527_M22708Jul22_08_28_38.png.f843374aba7d460bae35a8ebfb17a0b7.png

1402397862_NGC733108Jul22_08_10_56.png.4ec94a1bedbf563e8e149ded0ccc6152.png

540902411_EasternVeil08Jul22_08_21_20.png.208cff4fd95ff76eb00af6399394d114.png

204699600_CrescentNeb08Jul22_08_33_35.png.2733dacc767e259e7ea31cbbcb4f6ff4.png

424191695_Cocoon08Jul22_08_19_32.png.7fba2eeb98ad870d65b262efd4770bdf.png

1179876017_M1508Jul22_08_14_40.png.9b5be1175799a87031a578b1eb1b7d4d.png

Edited by RobertI
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Posted (edited)
8 minutes ago, happy-kat said:

Particularly like the last one.

The bottom right legend is showing 0ms?

Thanks! Yes the exposures are showing as 0ms because the captures were being done in Starlight Live, so Jocular did not know the exposure length. The reason for using Starlight Live was that Jocular did not recognise the Lodestar for capturing, so had to work around.

Edited by RobertI
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30 minutes ago, Steve in Boulder said:

Jocular will read the exposure time from the FITS header, so Starlight Live must not be recording it. 

Oh right, thanks for pointing out, incorrect assumption on my part. Would be interested to hear if anyone else has had same problem with SLL. 

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Posted (edited)

Lovely shots Rob. Amazing what can be done with a fast 66mm scope.

SLL is one of the few capture programs that don't write exposure time into the header. I used to estimate it from sub arrival time intervals but that wasn't universally reliable. There is a way to read exposure info from the user but this is being simplified in the upcoming version so I won't confuse things by going into the details here. I'm also hoping to provide the option to edit the exposure info for previous captures soon. 

Hot pixel removal ought to be on by default, so in general there is no need to use median just to remove them. For the odd frame with satellite trails I often just deselect the offending sub, but for slow-moving trails I tend to use the 90/80/70% percentile options if i have enough frames. SNR is slightly worse with median than with these other options, but it is pretty marginal.

 

 

Edited by Martin Meredith
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1 hour ago, Martin Meredith said:

Lovely shots Rob. Amazing what can be done with a fast 66mm scope.

SLL is one of the few capture programs that don't write exposure time into the header. I used to estimate it from sub arrival time intervals but that wasn't universally reliable. There is a way to read exposure info from the user but this is being simplified in the upcoming version so I won't confuse things by going into the details here. I'm also hoping to provide the option to edit the exposure info for previous captures soon. 

Hot pixel removal ought to be on by default, so in general there is no need to use median just to remove them. For the odd frame with satellite trails I often just deselect the offending sub, but for slow-moving trails I tend to use the 90/80/70% percentile options if i have enough frames. SNR is slightly worse with median than with these other options, but it is pretty marginal.

 

 

Thanks Martin, it was satisfying to get a self-aligning, wide-field setup from bits of equipment I had lying around in the garage!!  I did notice a very slight increase in noise when using Median but it did seem to remove hot pixel 'trails' (I assume that's what they were) - see below. It's not an issue as the results were great, but you might have some insight....

Mean:

Mean.png.b0727e10211d5068cf344fba04a0ac55.png

Median:

Median.png.1297187f05ab7bb05b71e6ce14e2a481.png

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Could you check you have hot pixel removal set to on? (Config icon then badpixelmap). There is also a parameter that controls the outlier rejection threshold. Try lowering it slightly if the hot pixels are not removed. To rerun the stack after any changes, just hit the recompute stack icon (at around 11 o'clock on the eyepiece).

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Posted (edited)
2 hours ago, Martin Meredith said:

Could you check you have hot pixel removal set to on? (Config icon then badpixelmap). There is also a parameter that controls the outlier rejection threshold. Try lowering it slightly if the hot pixels are not removed. To rerun the stack after any changes, just hit the recompute stack icon (at around 11 o'clock on the eyepiece).

Thanks Martin. Just checked and I did have the bad pixel set to on -  I tried changing the parameter to lower values and rerunning, but didn't seem to make any difference. Also tried restarting Jocular, but no joy.  

Edited by RobertI
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Odd. I've not had a failure in hot pixel mapping so far and the feature has been in since the start, but then perhaps its not been tried with such a short focal length (not that it ought to make much difference). Perhaps worth checking the logs (in joculardata/logs) to see if there is anything odd going on that is preventing the hot pixel mapping from getting deployed. Feel free to send me the log 🙂

 

 

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Hi Rob,

Super results. I am sort of envious of the set up - wide fov is so good for setting the context and frequently show the beauty of the heavens, unlike my set up. 

I use SLL/Jocular with my ultrastar. To set the time for subs: First decide what the sub time will be in SLL, then go over to Jocular and hit the sub time button (just below the camera on the right - see below - I placed the cursor on the 7s, ) and up will come the pre-programmed sub times. Then activate the desired time, or if it is not there then  create a user defined time and activate it. Hope that makes sense. Just out of interest, I never use median. I also regularly delete subs as they come in, if they have satellite trails or they have significant star wobble if the conditions are unsteady.

Enjoy the journey.

Mike

 

image.thumb.png.cbd1bddc90a472b5b3ee8b137a903be8.png

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15 hours ago, Steve in Boulder said:

By the way, the annotation feature is really nice to use with galaxy groups like NGC 7331.  

Thanks Steve - I assuming this is the platesolving feature - I've tried this and always get "unknown DSO". I've set the focal length, pixel size and orientation (and tried all combinations of orientation) but no joy yet unfortunately.

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12 hours ago, Mike JW said:

Hi Rob,

Super results. I am sort of envious of the set up - wide fov is so good for setting the context and frequently show the beauty of the heavens, unlike my set up. 

I use SLL/Jocular with my ultrastar. To set the time for subs: First decide what the sub time will be in SLL, then go over to Jocular and hit the sub time button (just below the camera on the right - see below - I placed the cursor on the 7s, ) and up will come the pre-programmed sub times. Then activate the desired time, or if it is not there then  create a user defined time and activate it. Hope that makes sense. Just out of interest, I never use median. I also regularly delete subs as they come in, if they have satellite trails or they have significant star wobble if the conditions are unsteady.

Enjoy the journey.

Mike

 

image.thumb.png.cbd1bddc90a472b5b3ee8b137a903be8.png

Thanks Mike I shall give this a go. :) 

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On 09/07/2022 at 17:53, Martin Meredith said:

Odd. I've not had a failure in hot pixel mapping so far and the feature has been in since the start, but then perhaps its not been tried with such a short focal length (not that it ought to make much difference). Perhaps worth checking the logs (in joculardata/logs) to see if there is anything odd going on that is preventing the hot pixel mapping from getting deployed. Feel free to send me the log 🙂

 

 

Thanks Martin, I had a quick look at the log but can't conclude much I'm afraid - log attached if you do get a chance to have a look. 👍

jocular.log

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4 hours ago, RobertI said:

Thanks Steve - I assuming this is the platesolving feature - I've tried this and always get "unknown DSO". I've set the focal length, pixel size and orientation (and tried all combinations of orientation) but no joy yet unfortunately.

The platesolver needs a little bit more info: enter the primary DSO name via the DSO button.   Then click “solve.”   

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Hi Rob,

To illustrate Steve's platesolve comment.

Just loaded up the subs for my 7331


image.thumb.png.cfe7bb8e5ea06e633013d752d2863a2d.png

 

 

 

 

 

 

 

 

 

 

 

 

 

Next I hit plate solve and note how the image has been automatically rotated and check out bottom right where plate solver confirms it has solved the image

image.thumb.png.06d6aff66588dbf8cea02bc74c3cf547.png

 

 

 

 

 

 

 

 

 

 

 

Next I have moved the slider that says 'off' on the outside of the ring and you get more and more objects being highlighted with circles and also the label NGC 7331 added. This is very useful because it is indicating a variety of objects for further investigating.

image.thumb.png.d936d914521a901821748807308c969a.png

 

 

 

 

 

 

 

 

 

 

 

I then clicked on the objects that interested me and up comes the label. When I had done that I moved the slider back to where it says PIN and hey presto they are now pinned. (any object that I click on to bring up the label can have its label removed by clicking on it before returning to PIN).

image.thumb.png.8c90be050f1636ef948cd8c17d16a5ec.png

and finally your shot shows that lovely wide field view and mine gives the close up view and more detail - always great when people add in their shots using different gear - it adds to the interest of the observation.

Mike

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Posted (edited)

Thanks for the guidance Steve and Mike -  just had a play with my own Arp images and Jocular's included Arp 186 image (all available for selection in the DSO catalogue) and I get the "no match" message - I've tried all up/down and left/right combinations - not sure what's wrong?

Lovely capture of NGC7331 Mike. 👍

Edited by RobertI
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5 minutes ago, RobertI said:

Thanks for the guidance Steve and Mike -  just had a play with my own Arp images and Jocular's included Arp 186 image (all available for selection in the DSO catalogue) and I get the "no match" message - I've tried all up/down and left/right combinations - not sure what's wrong?

Lovely capture of NGC7331 Mike. 👍

I'm not sure what the focal length and pixel size were for Jocular's included Arp 186 images.  It's important to get those fairly close.  It looks like you're running your APO with a reducer, perhaps you need to enter the reduced focal length?

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7 hours ago, Mike JW said:

Hi Rob,

To illustrate Steve's platesolve comment.

Just loaded up the subs for my 7331


image.thumb.png.cfe7bb8e5ea06e633013d752d2863a2d.png

 

 

 

 

 

 

 

 

 

 

 

 

 

Next I hit plate solve and note how the image has been automatically rotated and check out bottom right where plate solver confirms it has solved the image

image.thumb.png.06d6aff66588dbf8cea02bc74c3cf547.png

 

 

 

 

 

 

 

 

 

 

 

Next I have moved the slider that says 'off' on the outside of the ring and you get more and more objects being highlighted with circles and also the label NGC 7331 added. This is very useful because it is indicating a variety of objects for further investigating.

image.thumb.png.d936d914521a901821748807308c969a.png

 

 

 

 

 

 

 

 

 

 

 

I then clicked on the objects that interested me and up comes the label. When I had done that I moved the slider back to where it says PIN and hey presto they are now pinned. (any object that I click on to bring up the label can have its label removed by clicking on it before returning to PIN).

image.thumb.png.8c90be050f1636ef948cd8c17d16a5ec.png

and finally your shot shows that lovely wide field view and mine gives the close up view and more detail - always great when people add in their shots using different gear - it adds to the interest of the observation.

Mike

Very nice example, Mike!  I enjoy gradually increasing the depth of the annotation and seeing what magnitude PGC galaxies and quasars I was able to catch.  

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Rob, check you have the binning info correct - go into configure menu. See below for my set up. I mostly use no binning but if I use 2x2 binning then I must change things in the binning section

Mike

image.thumb.png.81b51b0dab51f366a798796148fb6ef6.png

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5 minutes ago, Steve in Boulder said:

I'm not sure what the focal length and pixel size were for Jocular's included Arp 186 images.  It's important to get those fairly close.  It looks like you're running your APO with a reducer, perhaps you need to enter the reduced focal length?

Also, just to check.  When you start up Jocular and before you run a plate-solve, does it say "available" in the lower right hand corner, below "platesolver"?  If not, perhaps you put the platesolving catalog (pardon my Americanese) in the "catalogues" subdirectory instead of a separate "platesolving" subdirectory?

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Thanks for your very speedy help guys - it's late and I didn't think about the focal length - I entered the correct FL of 700mm for my old Arp 12 image and success!

1986484888_Arp12.thumb.png.6dbe81de837c785c37d16c439318e6c2.png

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