jupiter - how to improve

[chemtom24]

first efforts of jupiter with neximage and 200p newt on heq5.

must have been around 2000 frames @30fps, with a 6x barlow - 2x + 3x) unfortunately my neximage wont reload its default settings so im stuck with black and white for now.

question is, how can i improve image quality? do i need a bigger scope or a better camera?

seeing was pretty decent last night, and it was also my first real sight of jupiter (first was last year with a 130 - a bright white ball with one band) and it blew me away how much i could see, and i swear i saw colour i took the advice of looking at my bright headlamp just before looking through the ep to increase my colour vision

[Kokatha man]

Hi C24 - tbh, I really don't think staring at a headlamp before looking through a scope is going to do anything other than almost totally blind you to all the nuances of fine detail etc.....give that "suggestion" a real heave-ho imho mate....!

With an 8" newt you are capable of good images of the planets - first and foremost are the seeing conditions and the collimation of the scope: it's something you really do need to get a good handle on, and I advise checking it before each imaging session using a star near to the planet you wish to image rather than any collimating tool.....meaning get a star onscreen on your laptop via the camera and take it out of focus till you can see a series of concentric circular rings.....if the image is dancing madly give the night a miss - it means seeing is bad!

What you're going to try and do is get those rings nice and uniformly concentric within each other, ie the spacing is even/uniform between each ring layer all the way around.

If the secondary mirror has been properly set up this uniform series of rings (known as diffraction rings) can be achieved by tweaking the primary mirror adjuster screws at the back of the scope - just make sure you get that ring image central in the lappy screen to examine it and then after each tweak re-centre it and check before seeing what more tweaking is needed - you' soon get the hang of which screws are making things better or worse!

With a scope in good collimation, some decent seeing and trying as hard as possible to get as accurate/sharp a focus as you can some good images will eventuate.....rather than trying to stack barlows start off with a single barlow (the greater the barlow "power" the harder it is to get a good image in less than very good seeing, as well as being harder to get the image on the camera/sensor/lappy screen and harder to focus!)

It's better to use an extension tube with a single barlow (this increases its' "power" or the image scale you create for the optical train) because you're sticking less "glass" in said optical train.....seeing, collimation, focus and sensible image scales with good capture settings will bag you some great images with a bit of pratice!

Having said all that, you haven't done too badly at all for your first effort, it's something to be proud of and I'm sure if you persevere you'll be producing some top images very soon....!:)

[Ags]

It's true dark adaptation is not required for planets (and indeed if you are not dark adapted you may have better color vision) but I think staring at bright lights won't help either.

[chemtom24]

thanks kokatha hehe maybe il give the bright light thing a miss next time! will try again tonight if weather permits.

An extension tube rather than a lot of barlows - great idea! image quality certainly did decrease considerably when using two.

Will check collimation on the laptop screen - sounds alot easier than using a cheshire in any case, cos im not big enough to reach the primary screws AND look through the ep at the same time.

Thanks again

tom

[Clayton]

Thats a nice start.

[chemtom24]

managed to put one of the raw av'ss through aviraw and get a colour avi which i ran through registax. an improvement i think

only downside is that the raw mode goes at 5fps. meh, cant have it both ways.

EDIT - i beleive you can just make out the giant red spot?

[Kokatha man]

Yes, it is the GRS C24 - a fine effort there....!

Onscreen collimation using a star is not only far easier for one person to do by themselves, but it is more accurte than any method with cheshires or laser barlows etc because you're actually collimating with the actual optical train you're intending to use (ie, the imaging train!)

[ScubaMike]

Second image is great improvement ChemTom,

You must be chuffed to be improving so quickly. I would be well pleased.

Surprised you didn't capture any of the moons...

That is definately the GRS, good capture.

[lukebl]

I don't know much about the the Neximage, but I would suggest that your imaging at 30fps results in a loss of quality through file compression. It's the same sensor as the SPC900s, and when imaging planets, I generally use 10 or even 5fps. It improves image quality hugely, although you have to make sure your captures aren't so long that you get blurring due to Jupiter's rapid rotation. Keep it at less than 3 mins.

[chemtom24]

yes im very happy with it! it was captured during the same session but i changed the fps to 5, which happened to put the camera into raw mode. then after i poste dhere i remembered aviraw can 'recolour' the raw B+W so i tried it and got the colour image next time im gonna image in raw but use an extension tube/barlow to get a larger image, and hopefully more detail!

not sure i had the settings high enough for the cam to get a moon??

[ScubaMike]

I'm going to try reducing the frame rate too next time I get out.

Thanks for the detail ChemTom, good to learn from others trials & experiments.

[Cloudwatcher]

not sure i had the settings high enough for the cam to get a moon??

I think you have two off to the right........

[chemtom24]

blimey so i do! didnt even notice them in the original until i saw your versio and looked for them thanks cloudwatcher.

in future, if i wanted to include the moons, would i have to superimpose them, eg edit the image to bring out the moons (which would blow out jupiter), and then place them into a versio which is edited for jupiter?

[Gina]

I advise checking it before each imaging session using a star near to the planet you wish to image rather than any collimating tool.....meaning get a star onscreen on your laptop via the camera and take it out of focus till you can see a series of concentric circular rings.....if the image is dancing madly give the night a miss - it means seeing is bad!

What you're going to try and do is get those rings nice and uniformly concentric within each other, ie the spacing is even/uniform between each ring layer all the way around.

If the secondary mirror has been properly set up this uniform series of rings (known as diffraction rings) can be achieved by tweaking the primary mirror adjuster screws at the back of the scope - just make sure you get that ring image central in the lappy screen to examine it and then after each tweak re-centre it and check before seeing what more tweaking is needed - you' soon get the hang of which screws are making things better or worse!

With a scope in good collimation, some decent seeing and trying as hard as possible to get as accurate/sharp a focus as you can some good images will eventuate.....rather than trying to stack barlows start off with a single barlow (the greater the barlow "power" the harder it is to get a good image in less than very good seeing, as well as being harder to get the image on the camera/sensor/lappy screen and harder to focus!)

It's better to use an extension tube with a single barlow (this increases its' "power" or the image scale you create for the optical train) because you're sticking less "glass" in said optical train.....seeing, collimation, focus and sensible image scales with good capture settings will bag you some great images with a bit of pratice!

Very useful advice - thanks very much :) I haven't really got into this much as yet and much appreciate the collimation advice. I was wondering what I should buy for collimating And using an extension tube rather than stacking Barlows is very useful advice too

Much appreciated.

[Kokatha man]

Hi Gina - as I've said above, collimating onscreen is far better when imaging but for visual anything from the good old cheshire to the many different types of barlowed collimators are the go.

Tom - bringing out the moons in your captures is simple.....just crank up the levels in your processed image in (say) photoshop and the moons will sudddenly appear - note carefully where they are and then cancel the levels adjustment you've just done and often you'll find you can still see the moons very faintly - tilting the screen back can assist therein.

Use the circular marquee tool to draw a very tight circle around each moon (or use the Quick selection tool instead) and when you've done this correctly you can raise their levels without affecting the planet's.....try for very small disks that are neither too large nor bright in appearance.....a little practise will soon have you working out the right touch....!

[Gina]

Hi Gina - as I've said above, collimating onscreen is far better when imaging but for visual anything from the good old cheshire to the many different types of barlowed collimators are the go.

Thanks Imaging is my main interest but that doesn't stop me having a look through an eyepiece or two.