23 replies to this topic

[dcaponeii]

After finishing my Saturn captures this morning and waiting for the cloud bank to pass I was able to capture the bulk of the Io shadow transit this morning.  The GRS made it just past the meridian and the Io transit was well underway before clouds came back and ended my campaign of the overnight hours.

 

I've got the individual stacks processed in Wavesharp (I decided to go back to 60s captures using Autocapture in AS!4.  See I DO listen Grant....sometimes!!

 

Working through WinJuPOS now to create 5-image derotations as the seeing was pretty good for part of the encounter.

 

For now here is a GIF to wet your whistle and a pointer to an APNG (Yes Andrew, Cor got the APNG builder to work properly during the past day.)  This is 91 60s stacks of 15% of about 7000 frames when Io is far afield and about 10,000 frames as Io reaches the disk.  (I made two changes to progressive smaller ROI's during the captures as the alt/az mount placed Jupiter and Io in an almost vertical orientation.  In Wavesharp I rotated and crop the batch stack of images so that Io fit inside this ROI throughout.

 

 

Here is the link to the matching APNG I put into my gallery:  https://www.cloudyni...07_15787637.png

 

WARNING:  That APNG is 18MB or so in size so don't choose the link if you are prone to choking your computer with big files.

 

Seeing was variable throughout and high clouds were a nearly constant menace requiring at times the use of auto-histogram to keep the captures underway.  In a few cases I made the switch to auto-histogram in mid-capture but AS!4 did not seem to mind.  I'm sure it made a mess of the capture log.

Edited by dcaponeii, 06 September 2024 - 08:47 PM.

[dcaponeii]

I completed the first set of 5-image derotatoins in WinJuPOS.  Each of the frames in this animation are one of these 18 5-image derotations.  There is no overlap yet between the frames used for the derotations.  The advantage is that there are only 18 frames in the animation.  The disdvantage is it's jumpier than I prefer.  I'll get the full 90 frame animation using overlapping derotations (as soon as I can)

 

Here is a uni-directional GIF to give you something to see here.

 

But you should look at the APNG in the gallery here: https://www.cloudyni...207_1469609.png

 

It's only a 4MB file this time (and loops in reverse) so hopefully won't give anyone using one of those antique dial-up modems too much trouble.  "AOL...You've got MAIL!!"

[dcaponeii]

I grabbed one of the 5-image derotations to see how it looks as a finished image.  Not the best in the world but pretty good I think.  Maybe a bit too much of everything but there details are there.  By the time Io was on the disk I was using an ROI of 800x600 without a cut box.  This yielded about 170 fps with a 5.5ms exposure so pretty close to using all the photons.  If you squint a bit it looks like the GRS has a smiley face in the center.

 

[edsplace]

That is an awesome animation. Great capture glad you didn't have clouds. What was the equipment

[dcaponeii]

That is an awesome animation. Great capture glad you didn't have clouds. What was the equipment

The 16" DOB with my ASI676MC camera, 2x barlow and ADC.

[Tulloch]

Great images and animations Don, glad the apng option works well.

 

Personally I've never liked forwards and backwards animations, I much prefer them to move in the direction thay move in real life, stop, then start again. The added advantage is that you can either add more frames or make them larger to fit in with the file size restrictions . But, each to their own.

 

 

It's only a 4MB file this time (and loops in reverse) so hopefully won't give anyone using one of those antique dial-up modems too much trouble. 

Surely nobody is using dial-up modems anymore 

[marvyyk]

So cool! Awesome image and animation! 

[dcaponeii]

Great images and animations Don, glad the apng option works well.

 

Personally I've never liked forwards and backwards animations, I much prefer them to move in the direction thay move in real life, stop, then start again. The added advantage is that you can either add more frames or make them larger to fit in with the file size restrictions . But, each to their own.

 

 

Surely nobody is using dial-up modems anymore 

That's a personal preference I think since the Universe does not stop and jump back to the beginning either.  Cosmologists in the past have theorized that the Universe could end in "The Big Crunch" although the invention of Dark Energy makes that less likely as long as you ignore the current Hubble tension problem.  Just think of my animations as a little bit of the big crunch.  If people are not using dial up modems any longer than what the heck is there a 500kB limit on images presented in the thread???  They are out there and they know who they are!!!
 

[Tulloch]

If people are not using dial up modems any longer than what the heck is there a 500kB limit on images presented in the thread???  They are out there and they know who they are!!!

Probably because this is a free website that's part of an Astronomy shop who has to pay for the storage somewhere out of its own profits. This isn't AstroBin where users pay an annual subscription and can store images as large as they like. The threads were probably only meant to originally show text as people discuss astronomy related topics.

 

In any event, I think having an option to provide a link to a larger image in the gallery works quite well - you can post your link as an image, rather a text string...

 

<7MB animation in my Gallery of a more favourable time for Southern hemisphere imaging of Jupiter>

Edited by Tulloch, 06 September 2024 - 05:49 PM.

[dcaponeii]

Probably because this is a free website that's part of an Astronomy shop who has to pay for the storage somewhere out of its own profits. This isn't AstroBin where users pay an annual subscription and can store images as large as they like. The threads were probably only meant to originally show text as people discuss astronomy related topics.

 

In any event, I think having an option to provide a link to a larger image in the gallery works quite well - you can post your link as an image, rather a text string...

 

<7MB animation in my Gallery of a more favourable time for Southern hemisphere imaging of Jupiter>

Need to figure out how to do that.  I tried linking images from the gallery in the Lunar Forum and got whacked by the moderator.  Can you explain what you're doing to create the link
 

[Tulloch]

Need to figure out how to do that.  I tried linking images from the gallery in the Lunar Forum and got whacked by the moderator.  Can you explain what you're doing to create the link

Hmm, that's all I did, just added a Gallery image using the "My Media" button and chose the image I wanted. Nobody has ever said anything to me about that before (but maybe they are about to  ) ...

 

Edited by Tulloch, 06 September 2024 - 06:11 PM.

[dcaponeii]

Hmm, that's all I did, just added a Gallery image using the "My Media" button and chose the image I wanted. Nobody has ever said anything to me about that before (but maybe they are about to  ) ...

 

CN add gallery image.JPG

Maybe I'm doing it wrong.  I've been using the image link symbol and pasting the image link in there.

[dcaponeii]

 

 

This is a test. I never used the My Media button before.  It works!!.  You have to click on the link to make the APNG run but that's easy to do.

Edited by dcaponeii, 06 September 2024 - 07:01 PM.

[dcaponeii]

Here is an 87 frame animation of the Io shadow transit.  Along the way the GRS comes into view and the Io transit begins.  Each frame is a 5-image derotation of 60s stacks.  Andrew showed me this My Media button so this should display the APNG below if I'm doing this right.

 

Seeing was poor as the clouds first departed the area and the 38 degree altitude didn't help.  Things get much better as the animation progresses.  You need to click the image for the APNG to play.  EDIT:  I reprocessed the final 65 images of the set as the input frames to WinJuPOS were a bit too sharp.  Now Io is not blown out against the background of space and for the most part the halo around Io's shadow is gone.

 

 

Edited by dcaponeii, 07 September 2024 - 08:51 AM.

[Tulloch]

Here is an 87 frame animation of the Io shadow transit.  Along the way the GRS comes into view and the Io transit begins.  Each frame is a 5-image derotation of 60s stacks.  Andrew showed me this My Media button so this should display the APNG below if I'm doing this right.

 

Seeing was poor as the clouds first departed the area and the 38 degree altitude didn't help.  Things get much better as the animation progresses.  You need to click the image for the APNG to play.

 

That's really impressive - now all you need is the crossed-eyed stereo 3D version of the transit

[dcaponeii]

That's really impressive - now all you need is the crossed-eyed stereo 3D version of the transit

Noooooooooooo!!!!!!!!!  I can't do those when Iook at them anyway.
 

[dcaponeii]

I replaced the APNG on Panel #14 with a less sharpened version.  Have a look.

[Tulloch]

I replaced the APNG on Panel #14 with a less sharpened version.  Have a look.

I preferred the sharper one

[Mitchell Duke]

I agree the sharper one is best.

[dcaponeii]

I preferred the sharper one

I was prodded strongly into the less sharp version due to Io being blown out and the halo.

[Tulloch]

I was prodded strongly into the less sharp version due to Io being blown out and the halo.

I wonder if there's a way to modify the sharpening routine to reduce the levels on very sharp transitions (such as what you see on a bright moon or a dark shadow) to avoid this ringing. Photoshop has an option in its Unsharp Mask tool called "threshold" which I assume does something like this, maybe this can be added to the wavelet sharpening routines in WaveSharp?

 

Edited by Tulloch, 07 September 2024 - 07:04 PM.

[Kokatha man]

I was prodded strongly into the less sharp version due to Io being blown out and the halo.

I didn't see the sharper version Don - unless I missed it here - but apart from the halo around the shadow in Post #14 it's pretty nice! A bit of variation in the seeing across the frames but it's pretty unusual to not encounter that unless you create one of those "phoney" WJ "skin" ones.

[dcaponeii]

I didn't see the sharper version Don - unless I missed it here - but apart from the halo around the shadow in Post #14 it's pretty nice! A bit of variation in the seeing across the frames but it's pretty unusual to not encounter that unless you create one of those "phoney" WJ "skin" ones.

I try not to mess with Phoney ones. The sharper one looked like Io had a corona!!! You didn’t miss much. It’s still in the gallery if you really want to see it.

[dcaponeii]

I wonder if there's a way to modify the sharpening routine to reduce the levels on very sharp transitions (such as what you see on a bright moon or a dark shadow) to avoid this ringing. Photoshop has an option in its Unsharp Mask tool called "threshold" which I assume does something like this, maybe this can be added to the wavelet sharpening routines in WaveSharp?

Unsharp mask threshhold.JPG

There is a threshold in the bilateral filter option. I’ll check on Gaussian wavelet. Most of the “halo” is the artifacts from WinJuPOS in the newer animation.