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Starlog April 26th, 2026, 9:31 p.m. local time
I am still getting used to a far more automated imaging setup. And while this latest capture of Jupiter is serviceable, I feel I can do better. Unfortunately time is currently not on my side, as Jupiter is rapidly falling into the West, and I will likely have to resume my experiments with the largest planet later this year.
Most noteworthy to this session was the inclusion of Celestron’s StarSense Autoguider. An absurdly priced piece of equipment, I almost opted for a less expensive option from ZWO. But I felt keeping within Celestron’s ecosystem via their CPWI software was worth the cost pain (and I am sure Celestron has priced their equipment accordingly; they are now a near-monopoly in the amateur astronomy market, after all).
I was deeply worried about whether the SSAG would gel with my SCT, control mount, and laptop. Fortunately, after the needed firmware update, everything worked perfectly. But good grief, their firmware updater requires you to install JAVA, yes JAVA. Like this is 2003.
But once within CPWI, I was amazing how easily the SSAG worked. It was a little challenge to truly center align the SSAG and telescope i.e. to ensure the selected target is centered in the telescope’s view and not in the finder’s camera. This will require more practice.
Fine-tuning my remote WiFi was another challenge, but one I feel I have satisfactorily resolved. My WiFi 7 network allows for a multi-link setup, which leverages both the 5 GHz and 6 GHz bands with multiple streams. The speed of this, indoors, is incredible, but I discovered it is positively horrid connecting from outside. I use a separate USB adapter with 10 ft USB cable to get the signal as close to the house as possible, and once I switched it back to my normal 5 GHz network, the connection became extremely stable between the outside control laptop and my desktop in my home office.
But the primary aspect I must work on is focusing. The motorized focuser allows greater precision through my focusing attempts than ever, but I still feel the final results are off too much. While my window for Jupiter is almost gone, I hope to resume focusing practice with the Moon and, in a few months, Saturn.
Equipment Used:
- Celestron NexStar Evolution 9.25 Schmidt-Cassegrain
- ZWO ASI676MC planetary camera
- Software for telescope control: CPWI
- Software for capturing: ASICAP
- – Capture Area Size = 1280 * 720
- – Capture Limit = 90 s
- – Colour Format = RAW8
- – Debayer Preview = ON
- – Debayer Type = RGGB
- – Exposure = 7.758ms
- – Frame Count = 11509
- – Gain = 114
- – Temperature = 19.5 C
- – TimeZone = -5
- No Barlow, no filter
- Created from a 90s video, best 50% of frames via Autostakkert
- Focusing via Celestron’s motorized focuser in CPWI
- Software for post-processing:
- – PIPP
- – Autostakkert 4
- – WaveSharp 3
- PaintShop Pro for minor touch-ups
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One thing that always interests me is the number of frames that different astro-imagers take initially and the number of best frames which are stacked.
I haven’t imaged Jupiter for quite a while but I never exceeded 2000 frames. I then usually stacked the best 10-20%.
Your 111,509 frame count is a massive number (equivalent to about 14-15 minutes) which would surely have severely tested my system if I attempted it!
A 14-15 minutes exposure is a long time with Jupiter’s fast rotation speed. I’ve seen recommended times published in various places and I thought the recommended limit was about 10 minutes or less.
But it is an excellent image of Jupiter.
✅
Thanks Roger. Unless I am mistaken, the core rule for Jupiter exposure is no more than about 90 seconds, regardless of equipment. I know there are techniques to correct for the rotation, hence longer exposures, but my images have never been good enough to start considering those.
The ASI676MC was essentially made for my SCT and its focal length, as the senor is its perfect size for planetary imaging. I assume the sensor is far smaller than what you or any deep sky photographer uses, hence far less heat buildup. The more I automate my setup for planetary, the more I appreciate how much greater the complexity of deep sky imaging is, having to deal with cooling, long exposures, etc.
I do have Celestron’s wedge which converts my Alt-Az mount to equatorial, but I have not used it yet. Now that I have the equipment automation mostly figured out, I plan to use the wedge in a few months when I start Saturn imaging. That should allow for many minutes of continuous exposure.
Also, regarding stacking, I have been using 35%, 50%, and 85% for a while, and comparing which appear best in the final images. But that model was for my old paradigm, before my ZWO planetary camera. I should re-run in the 10-20% range and compare the results.