August 10th, 2022, 1:10 a.m. local time
“Planet season” officially began for me this early morning as I observed and photographed both Saturn and Jupiter in these days and weeks before their respective oppositions.
I will cover Jupiter in a follow-up article, but first let’s talk about Saturn. Only days from its opposition, this was my first real opportunity to photograph our ringed planet since last year, and I had to do it after 1 a.m. The planet was ideally situated in the sky, almost due South. It made the required manual nudges of my Dobsonian relatively easy, since at the time Saturn was moving almost in a flat plane left-to-right from my vantage i.e. only horizontal telescope adjustments needed.
Relying on my astronomical journal (the real paper journal for which my website is named after), I was able to review my camera settings from 2021 and earlier. As I had written to myself, ISO 800 and exposure 30 consistently provided the best results for Saturn, making my ability to focus the only significant variable.
Out of three sets of four consecutive ~25 second videos, two came out excellent (in my opinion) but the third had a bad focus. Focusing on planets is not trivial. I am seriously considering getting my first “mod” for my homemade Dobsonian, which I built in 2016. It would be a more advanced focuser which would allow finer adjusments. No immediate plans, but I may explore options, especially if I can leverage the existing screw holes in the tube.
I also rely on a great catalog of trial-and-error presets in Registax to produce the final image. I have dozens of presents for Saturn, Jupiter, and Mars, covering what I have found to be the best slider adjustments, to produce the final images I post. In truth, I don’t know what I would do without them, as it would be far too time consuming to re-invent them every year when opposition season comes around again.
Summary of my equipment, settings, and software used:
- Telescope: Dobsonian reflector 254mm / 10″ (homemade)
- Camera: Canon EOS Rebel SL3
- Barlow: TeleVue Powermate x5 1.25″
- Filter: Baader Neodymium 1.25″
- Canon T ring and adapter
- Relevant camera settings:
- ISO 800
- Exposure: 30
- HD video at 60fps
- Created from four videos of about 25s each, best 60% of frames (via Autostakkert)
- Software for post-processing:
- Registax 6
- PaintShop Pro for minor touch-ups