Jupiter and Io – First Attempt with a Deep-Sky Setup - Forums

Topic starter

1 day ago

This is my first attempt at Jupiter using a setup that’s primarily optimized for deep-sky imaging: C8 EdgeHD with 0.7× reducer and ASI294MC Pro.

At this focal length, Jupiter comes out to roughly ~65 pixels across the disc, so resolution is clearly limited from the start. I recorded a short SER (~1.5 minutes at ~30 fps using ROI), and stacked the best ~25% of frames in AstroSurface. I’ve posted both the unsharpened stack and the processed version. The Weiner deconvolution probably pushes the data slightly — though it does help separate the bands.

What I found interesting is how strongly image scale dictates the entire outcome. With this configuration, you can definitely resolve the main belts and capture Io cleanly — but there’s simply no room for fine structure to exist in the data.

Link to detailed post: Jupiter and Io - What to Expect from a Deep-Sky Setup

I plan to repeat this at native focal length using an ASI676MC planetary camera, and possibly push further with a 2× Barlow to increase sampling.

For those who’ve made a similar transition:

At what point did you find the move to smaller pixels meaningfully changed the outcome?
How much practical gain did you see going from native focal length to 2× amplification on an 8" SCT?
In typical seeing, do you find 2× on a C8 genuinely productive — or mostly theoretical?

Interested in hearing real-world experience before I take the next step.

📷 jupiter-io-c8-edge-0.7xreducer-sharpened-astrosurface.jpg.jpg📷 jupiter-io-c8-edge-0.7x-stacked-unsharpened.jpg.jpeg

Well Written Helpful Insightful Respectful Engaging

andrea tasselli

Frequent contributor

1 day ago

I don't think it would be useful for you to go with a 2x barlow at the sampling achieved with the ASI676 @ ~0.2"/px as you are already correctly sampling your diffraction limit. Going beyond would only lower your SNR with hardly any gain.

Well Written Helpful Respectful Concise Engaging Supportive

Tony Gondola

Frequent contributor

12 hours ago

I would try it without the reducer for a start. Wait for good seeing and observe what you get. If you feel the result has improved then you could experiment with a Barlow or smaller pixel camera. It’s been well proven that over-sampling isn’t a sin when doing planetary lucky imaging. If you look around you’ll find that the best images out there follow the simple rule of ideal focal ratio = 5 to 7 times pixel size in microns.

for 4.6 micron pixels a factor of 5 is F/23

For 2 micron pixels the ideal f ratio is F/10

Given those numbers, the two micron camera with give you the best sampling and without a Barlow which is a benefit. Just keep in mind that the above rule really only works if you have excellent seeing, collimation, focus, enough frames and good processing technique.

Well Written Helpful Respectful Engaging Supportive