Jupiter help please(?)

[northcanadian]

Hi all:

This is from a run of Oct 19th...1000 of 1300 each RGB. Used the 9.25 SCT, a 2x barlow and ASI 120mm.   I notice that I did not quite line them up right in PS.  Could the lack of detail be not good seeing conditions,,,poor focus, or both?

Thanks for looking, and any suggestions would be  most welcome.

Cheers

Roger

[ronin]

Cannot help specifically however the post says 1000 of 1300 each RGB.

1000 of 1300 seems a lot, what I recall being told is 25-30% of the total so I would have expected about 300 of 1300. At 1000 you are throwing into the mix a lot of the poorer images.

The other factor is that Jupiter rotates fast, this point went through the grinder about 4 to 6 months back and I wonder if by the time you have obtained the R, the G and the B that the features have moved too much to be aligned and so you get an out of focus imaged, actually blurred.

When mentioned previously I think that people came up with time limits of 60-90 seconds on Jupiter before the rotation caused problems. I had read 90 seconds, however as normal several values and opinions came up. As it seems you took in effect 3 sets of exposures I would have thought that features had moved sufficently during the R,G and B exposures.

Off topic: What's the temperatures like in Northern Saskatchewan ?

[northcanadian]

Thank you for your advice....much appreciated. I think I went 50 seconds per capture on these. I shall try reprocessing some and next time out will try shorter runs.

It has been pretty mild here....hovering at about -5 C or so  at night...looks like the forecast is for -10 C for next few nights.  We have had a couple of snowfalls in the last week and icy, slushy highways...lots of vehicles in the ditch on highway south.

Cheers

Roger

[Owmuchonomy]

Hi Roger, I wonder what stacking software you use. Both Registax 6 and Autostakkert 2 have RGB align functions as part of the frame stacking process. Personally I prefer Autostakkert 2 as it is more user friendly. This is the best method then do your final tweaks in PS. As Ronin said, also use fewer frames so that the quality improves. The above software gives you a calibration curve which helps you choose how many frames to stack.

[northcanadian]

Thanks Chris.....I appreciate your help!  I am using R5, as I seem to get 'paving stone artifacts' with R6...not sure what I am doing wrong there(?)  I will try Autostakkert 2 and less frames ...as also recommended by ronin.

Cheers

Roger

[ronin]

50 seconds per capture would mean about a minimum of 5 minutes between first and last and not sure how much of the detail will have rotated sufficently to cause a problem. Always seems strange that anything would move that rapidly on a planetary scale.

If -5C to -10C is mild     whats cold?     

[Pete Presland]

Hi Roger i am using the same set up as yourself, C9.25 & ASI120mm. when i get everything right, i can capture 4,000 frames at each R,G,B channel at F10 in less than 3 1/2 minutes. a small region of interest, will help you to take fast frame rates.

seeing conditions, poor focus, collimation, are all things to be take into consideration. but as has been said i would not be stacking 1,000 frames out of 1,300. i only stack around 500-600 out of 4,000 enough to allow me to push the data and keep the noise levels low.

[northcanadian]

Hi Roger i am using the same set up as yourself, C9.25 & ASI120mm. when i get everything right, i can capture 4,000 frames at each R,G,B channel at F10 in less than 3 1/2 minutes. a small region of interest, will help you to take fast frame rates.

seeing conditions, poor focus, collimation, are all things to be take into consideration. but as has been said i would not be stacking 1,000 frames out of 1,300. i only stack around 500-600 out of 4,000 enough to allow me to push the data and keep the noise levels low.

Thanks Pete

I have admired your images here, and am hoping to learn how to get better results from the equipment I have (which I am quite happy with).

Using the 9.25 SCT to get the high frame rates at f10 would be using no barlow and a very small ROI....or...?  I understand the higher the barlow, the dimmer the image gets,  but I thought that image scale was important also for getting more detail(?)

Cheers

Roger

[Pete Presland]

It is but to be honest i stuggle with focussing at F10 (2350mm) with the conditions in the UK. I do using a powermate sometimes, but while the image scale is good it always semms to be a struggle to get a sharp image from it. with the crayford focusser and filter wheel i am probably quite a bit over the 2350mm focal length anyway. i would not hesitate to use my powermate in good seeing conditions though.