Saturn with ED80

[luka]

ED80 + 3x barlow + SPC900NC, processed with pipp (crop + quality selection) + registax (stacking + wavelets).

I lost the info but it was probably best 20% from 5min@10fps.

From 19th of April 2016.

[Mickoid (Michael)]

Great colour and detail for a 3 inch, well done.

[Anth10 (Anthony M)]

At 10 fps you've managed a successful image of this glorious planet. Excellent work.

[BeanerSA (Paul)]

Do you have a slightly larger version? It's the size of a postage stamp on my screen!

[janoskiss (Steve H)]

That looks brilliant. Hard to believe that's just 80mm of aperture!

You have a bit of a black-blue grid background sky sensor artefact there that you could probably easily eliminate but no big deal anyway.

@BeanerSA (Paul) You can use your browser's zoom function, usually CTRL & + (or =) keys. CTRL and mouse scroll wheel also work for me.

[luka]

Thank you for your comments.

Anth, I have to use 10fps as SPC900NC is only USB1. Any higher frame rate will end in lossy compression of the video and loss of details.

Paul, that is as big as it is. ED80 is quite a small scope (f=600mm) and not usually used for planetary work. I also only had 3x Barlow at the time. As Steve suggested you can zoom in with your browser. I will try stacked 3x and 2x Barlows once I fix my mount (broke the pulley ).

Steve, thank you for noticing the blue-ish background. I did not view the image on black before, only on gray. I fixed it below.

[janoskiss (Steve H)]

There is probably little point to chasing more image scale optically (by using barlows etc) with an 80mm scope. The diffraction limit of the scope is about 1.5 arc seconds, while the size of Saturn's disc is roughly 20 arc seconds. In your pic it's about 30 pixels in diameter, so already about 2.5x oversampled. That level of oversampling is a good thing because it helps with processing. But any more is unlikely to yield much better results.

It's precisely because of the inherently low angular resolution of the small aperture scope (which in digital terms more-or-less equates to about a 12x12 pixel frame for the planet's disc) is why getting an image as good as this is so impressive.

[Shiraz (Ray)]

Originally Posted by janoskiss

There is probably little point to chasing more image scale optically (by using barlows etc) with an 80mm scope. The diffraction limit of the scope is about 1.5 arc seconds, while the size of Saturn's disc is roughly 20 arc seconds. In your pic it's about 30 pixels in diameter, so already about 2.5x oversampled. That level of oversampling is a good thing because it helps with processing. But any more is unlikely to yield much better results.

It's precisely because of the inherently low angular resolution of the small aperture scope (which in digital terms more-or-less equates to about a 12x12 pixel frame for the planet's disc) is why getting an image as good as this is so impressive.

excellent image Luka.
the above is good advice - you have already got almost all of the information available from your small scope.

[luka]

Steve and Ray, thank you for your wise words. Very much appreciated and very helpful.

I should add that the main reason I use Barlows is to make the planetary images bigger. They may be blurrier but they are still bigger. A 5-6 pixel disc is just not much to look at, in my opinion. See for example my images of Mars with 2x Barlow and 2x + 3x stacked Barlows. I like the last one much more.

[janoskiss (Steve H)]

You can always blow up (aka upscale/resize) the image digitally. Given the limited resolution of the scope, the final result should be very similar either way.

[luka]

Haha, didn't think of that. It would also take 5sec to do compared to 20min trying to focus stacked Barlows.