Jupiter Second Attempt - 1st Feb 2015

[gnomus]

This is my second attempt at Jupiter.  (First - http://stargazerslounge.com/topic/233711-jupiter-first-attempt/).  I'm still some way away from the images seen in the Imaging/Planetary forum.  Not sure I understand about how to choose which f/number to be aiming for and so on.  This is my ZWO ASI120MM, through an 8 inch Celestron Edge.  I took 4000 frames through R, G and B filters and stacked the best 3000 in AS2.  I got lucky and managed to get all 4 Galilean moons in the frame.

Any feedback would be most helpful.  

[red dwalf]

excellent image, ideally you want to be trying for f20 or more if the seeing is good.

[Leveye]

Great image bravo!

[nickb2513]

Excellent!!

Was it Europa that they said could be earth like?

[gnomus]

excellent image, ideally you want to be trying for f20 or more if the seeing is good.

And I do that by using a 2x Barlow, right?

[red dwalf]

Correct, a half decent Barlow will do the job, you can also increase the image scale a little by moving the camera further back from the rear of the focuser, but a Barlow is easier to use.

[gnomus]

Here's the third image run.  I think this may be the best one.  I'd be interested in what others think.

[simmo39]

Stunning! You are already playing with the big boy!

[Blazar]

Hey Gnomus,

Nice detailed shots. The last one looks perhaps a little red to my eyes. did you tweek the colour balance?  Did you take an L channel?

So our Edge's are F10 (2032mm FL), when I was looking at this, a looked at the arc seconds per pixel to see what relation that had at native fl, as well as what happened when I added barlows etc to that FL, and how that affected the sampling....think the x2 is all we are going to get...not tried the x3....

[gnomus]

Correct, a half decent Barlow will do the job, you can also increase the image scale a little by moving the camera further back from the rear of the focuser, but a Barlow is easier to use.

So, how do I go about determining which f-stop is optimal?  I have to say that on the night I shot these videos, what I was seeing on the computer screen was not promising at all.  (I was rather surprised at what popped out of AS!2/Registax.)  The image I saw on the laptop led me to conclude that it would be a waste of time sticking my 2.5X PowerMate into the imaging chain.  

Also, does anyone have any 'recipes' for planetary sharpening in Registax?  I'm not sure if I'm doing too much or too little!

[gnomus]

Hey Gnomus,

Nice detailed shots. The last one looks perhaps a little red to my eyes. did you tweek the colour balance?  Did you take an L channel?

So our Edge's are F10 (2032mm FL), when I was looking at this, a looked at the arc seconds per pixel to see what relation that had at native fl, as well as what happened when I added barlows etc to that FL, and how that affected the sampling....think the x2 is all we are going to get...not tried the x3....

I derotated the planet in WinJUPOS (I'm not sure that made a lot of difference, but I wanted to do things 'correctly').  I then split the resulting image into RGB channels in PixInsight.  I did a Linear Fit on the resulting images (to balance the channels), and recombined them using LRGB combination - using the red channel as Luminance.  

I may have done a little saturation boost in Photoshop..... 

[gnomus]

Hey Gnomus,

...  The last one looks perhaps a little red to my eyes.....

Is this any better?

[Astrosurf]

Brilliant image! I'm jealous. They all look lovely to me.

Alexxx