struggling a little with jupiter any advice appreciated

[iwols]

stayed up late last night ,got focus and tracking bang on,even tried my adc ,but original capture poor.screenshot of capture and final process ,used sharpcap,as3 and registax 

2000 5ms frames any advice appreciated .C8 edge and asi178mc ccd ,thanks

Edited August 9, 2021 by iwols

[PEMS]

Is 2000 frames the best say of 20,000 frames, or did you only get 2000 frames and stack the lot ? Also how long was the video duration ? As 2000*5ms is only around 10 sec I assume you had a longer end to end duration.

Jupiter rotates fast, once round in 9.9 hours, that is fractionally over 36 degrees every hour or 0.6 degrees rotation every minute. The effect is that you do not have much time to capture a fair set of sharp enough frames before the rotation of Jupiter just moves the image round and so even stacking good sharp images results in a somewhat final slightly blurred stacked result. If the first and last frames of a 2 minute capture were perfect the result of stacking those 2 alone would have the features in different places.

If you had centering and tracking perfect then after 2 minutes the GRS (as an example) will have moved 1.2 degrees around the image of Jupiter. So the detail of Jupiter itself begins to get spread out.

Also as ever Jupiter is low at this time, and we have this rather annoying atmosphere to content with.

I expect that the problem is altitude of Jupiter, then you have to find the optimum balance or compromise between a short duration video to maintain the Jovian features as stationary but long enough to get sufficent good frames to stack. If you have the time maybe worth trying capture lengths of say 2 minutes, 3 minutes, 4 minutes and 5 minutes. Save each separately then perform a similar (identical) stack and process and see which result appears best. For stacking I would suggest best 5% or 10% of the frames. At least then you will have an idea of the limitations imposed on you, and the rest of us.

[iwols]

Thanks Pems ,i actually captured 2000 frames and used 50% to stack,cant remember what my frame rate was but from what i can remember about 20 secs but not sure,will try as you suggest,thanks for the advice  just expected the original video to be better👍

Edited August 9, 2021 by iwols

[Cosmic Geoff]

Your final image looks a bit soft to me. Try 5000 frames, use 20% and crank up the Registax to the point where the image starts to go grainy. 

Definitely use the ADC.

[iwols]

thanks Geoff👍

[vlaiv]

19 minutes ago, PEMS said:

Is 2000 frames the best say of 20,000 frames, or did you only get 2000 frames and stack the lot ? Also how long was the video duration ? As 2000*5ms is only around 10 sec I assume you had a longer end to end duration.

Jupiter rotates fast, once round in 9.9 hours, that is fractionally over 36 degrees every hour or 0.6 degrees rotation every minute. The effect is that you do not have much time to capture a fair set of sharp enough frames before the rotation of Jupiter just moves the image round and so even stacking good sharp images results in a somewhat final slightly blurred stacked result. If the first and last frames of a 2 minute capture were perfect the result of stacking those 2 alone would have the features in different places.

If you had centering and tracking perfect then after 2 minutes the GRS (as an example) will have moved 1.2 degrees around the image of Jupiter. So the detail of Jupiter itself begins to get spread out.

Also as ever Jupiter is low at this time, and we have this rather annoying atmosphere to content with.

I expect that the problem is altitude of Jupiter, then you have to find the optimum balance or compromise between a short duration video to maintain the Jovian features as stationary but long enough to get sufficent good frames to stack. If you have the time maybe worth trying capture lengths of say 2 minutes, 3 minutes, 4 minutes and 5 minutes. Save each separately then perform a similar (identical) stack and process and see which result appears best. For stacking I would suggest best 5% or 10% of the frames. At least then you will have an idea of the limitations imposed on you, and the rest of us.

Autostakkert!3 deals perfectly well with small amounts of rotation. Individual subs can have alignment points further away than rotation in about 2-3 minutes. You don't need to use derotation feature on movies up to few minutes long (that really depends on your working resolution).

I do agree that longer video is needed - I often capture 40000 subs in ~4 minute videos (about 160fps) and stack only small fraction of best (often around 10% or less).

1 hour ago, iwols said:

stayed up late last night ,got focus and tracking bang on,even tried my adc ,but original capture poor.screenshot of capture and final process ,used sharpcap,as3 and registax 

2000 5ms frames any advice appreciated .C8 edge and asi178mc ccd ,thanks

That is actually not bad image.

What alignment point size did you use? Try using something like 30px, and maybe post raw stack as wavelets are also a bit of an art (you need practice to get the most out of the image).

[powerlord]

Might be worth also using AS3 to do say a 30% and 10% output if the analysis shows a lot of variation between the frames.

And did you do wavelet stuff in registax ? there's a few tutorials around, but really imho all you really need to do is select diadic and gausian, whack the first slider all the way to the right if looks ok,  bring 2nd slider up as far as you can too. fiddle with small tweaks to the others, try a wee bit sharpening and noise redution (if it needs it) on the first set. job done.

stu

 

 

[neil phillips]

As Vlaiv says shoot for at least 2 or 3 minuets try 1/125 secs exposure Crop the capture area to speed the camera up

you will have over 22.000 frames. Image looks a bit small to me. But then i often get good results oversampling a bit. 

[CraigT82]

How are you focusing? You say focus was bang on so how do you know that? Bhatinov? 

Edited August 9, 2021 by CraigT82

[iwols]

focused with  bhatinov on a star ,then made slight adjustments when on jupiter craig

[CraigT82]

1 hour ago, iwols said:

focused with  bhatinov on a star ,then made slight adjustments when on jupiter craig

I personally always focus on the planet itself. I set the ROI and the zoom in a little bit on the preview screen. Then I switch the preview debayer on as I find it easier to focus on the colour image preview. Then I use the auto align function in firecapture to hold the image steady in the preview and then finally i'll run the focuser back and forth repeatedly, going through the focus zone multiple times trying to judge the point of critical focus.

I'll look at the details on the planet and try to judge when they are focused as sharply as possible. Often this isn't quite at the same point where the limb of the planet appears sharpest (no idea why this should be - maybe its my eyes playing tricks on me) but I always focus of the details on the disc, rather than the limb. 

Often it takes me a good 5 mins at least of running back and forth through the focus point before I'll decide on where the best focus is. 

I've never used a bhatinov mask or any other focus aids, including the edge/contrast /fwhm detection aids in firecapture. Always done it by eyeing up the detail visible in the screen. 

On Jupiter if the seeing is so bad I can barely make out the surface details on the preview, I'll move over to one of the Galillean moons instead and focus one of those until it's as small as I can make it before moving back to the planet. 

Anyways that's how I do it, might not work for you but maybe you could give it a try and see if it helps or not. 

[astroman001]

Craig is spot on with the focusing technique, it's what I do as well. Also notice an improvement in feature contrast at best focus.

An electric focuser is a must, you will be fortunate to find focus with the telescope focuser, too much vibration when you touch it.

Peter

[iwols]

5 hours ago, CraigT82 said:

I personally always focus on the planet itself. I set the ROI and the zoom in a little bit on the preview screen. Then I switch the preview debayer on as I find it easier to focus on the colour image preview. Then I use the auto align function in firecapture to hold the image steady in the preview and then finally i'll run the focuser back and forth repeatedly, going through the focus zone multiple times trying to judge the point of critical focus.

I'll look at the details on the planet and try to judge when they are focused as sharply as possible. Often this isn't quite at the same point where the limb of the planet appears sharpest (no idea why this should be - maybe its my eyes playing tricks on me) but I always focus of the details on the disc, rather than the limb. 

Often it takes me a good 5 mins at least of running back and forth through the focus point before I'll decide on where the best focus is. 

I've never used a bhatinov mask or any other focus aids, including the edge/contrast /fwhm detection aids in firecapture. Always done it by eyeing up the detail visible in the screen. 

On Jupiter if the seeing is so bad I can barely make out the surface details on the preview, I'll move over to one of the Galillean moons instead and focus one of those until it's as small as I can make it before moving back to the planet. 

Anyways that's how I do it, might not work for you but maybe you could give it a try and see if it helps or not. 

thanks craig excellent explanation,cant wait to try again

[iwols]

3 hours ago, astroman001 said:

Craig is spot on with the focusing technique, it's what I do as well. Also notice an improvement in feature contrast at best focus.

An electric focuser is a must, you will be fortunate to find focus with the telescope focuser, too much vibration when you touch it.

Peter

using the zwo eaf great piece of kit

[iwols]

whats a good roi to capture 640 or 1280? and does it effect quality

Edited August 9, 2021 by iwols

[CraigT82]

8 hours ago, iwols said:

whats a good roi to capture 640 or 1280? and does it effect quality

Smallest you can get away with really. Depends on the size of the planet - are you wanting to get moons in shot too?- and how accurate your tracking is (or how much the planet is moving around. Wind?)

I usually aim for about 500 square, but 640x480 would be good if that's one of the presets you have.

Doesn't affect quality at all. Just the file size of the video, and hence the file transfer speeds. Reducing the ROI size should allow to to get faster frame rates.

 

[iwols]

well new camera asi 426mc and results getting better,but still a way to go ,rather overcooked but not sure where to go now any advice please,would an infra red filter help?

 

Edited August 13, 2021 by iwols

[powerlord]

If there's no IR filter, I don't think that's ideal. I use a cheap 12 quid svbony job that works fine. ROI - I just draw a box around jupiter- you want smallest you can get away with for max frame rate. Do a few with bigger roi with some moons in and longer exposures if you want to composite those into final shot.