Jup/Sat conjunction, Mars, Uranus and Neptune - 14 Dec 2020
A hot (but still) night brought on some opportunities for imaging yesterday. After a few trips to Bunnings, I managed to kludge up a bracket to let me use my DSLR in landscape mode on my Evo mount so I could capture the upcoming conjunction, and was able to make a first attempt with the planets still some distance away from each other.
First image is Jupiter and Saturn taken with my Canon 700D and 70-300mm lens, which actually gives me 480mm due to the 1.6x factor of the smaller DSLR sensor. I then used the LiveView mode at 5x zoom to capture 2000 frames, stacked the best 50% in AS!3 using "Surface" mode and stabilization disabled, then played around with the levels in Photoshop. Three of Jupiter's moons are (barely) visible, Europa and Callisto are almost co-located at the bottom left of Jupiter. All moons shown brighter than captured.
No detail is evident at this short focal length, which concerns me a little as we approach the big day. Also, AS!3 doesn't like stacking multiple targets in planetary mode, I got around this using the surface mode, anyone have any tips on this?
Next I turned to Mars, using my normal setup of C9.25", 2.5x PM and ASI224MC. Still some detail evident, the dust/cloud is still visible at the 7 o'clock mark, Olympus Mons quite visible in this image. Image shown 150% captured size.
I hadn't looked at Uranus for a while, and since it was a dark night I thought I'd give it another go, I might even catch Miranda this time. But alas, it still evades me, hidden amongst the planet's glow. The moons (shown larger and brighter than actual) from bottom-left to top-right are Titania, Ariel, Umbriel and Oberon. Image shown 150% captured size.
Finally I thought about Neptune, and even though it was very low (26*) and almost due west (not my preferred direction for imaging due to my location east of Melbourne), I managed to find it (always the first struggle), and capture both it and Triton, with Triton again shown larger and brighter than actual. Image shown at twice the captured size.
Well done Andrew, Mars still showing detail even at > 13" and capturing Uranus and some of its moons is a treat as welll as Neptune and Triton. As for The Jupiter / Saturn show, it is a problematic one, Enough magnification to show Jupiters cloud bands and Saturns rings but getting them in the one field of view. Plus the added difficulty of clear western horizons and clear skies for the weekend and few days following.
Not looking good for around here, may have to pack the gear and drive a few 100 ks' inland away from the rain clouds.
Thanks Jeff, the conjunction is a puzzle without a good solution (without a large astro camera of course, I was considering that ASI178MC on the classifieds at the moment, but it probably wouldn't arrive in time).
At the moment, I'm looking at my 6" SCT with a f/6.3 reducer and ASI224MC, which should get me some detail on Jupiter, the rings on Saturn and maybe a moon or two. I tried the 9.25" with the reducer using the same capture settings for both planets to give this a couple of weeks ago, which isn't too bad...
Andrew,
Excellent images here to ponder over. I particularly like the two blue planets/ I’m very keen to understand your technique in capturing Uranus and Neptune. Is this done in the same way as with the closer planets? Is it a case of video stacking images as customary or is it more of a one shot high exposure take?
Very impressive - well done.
Thanks Anth, yep, the blue planets are done pretty much the same way as the larger ones. Of course, the shutter speeds and gain levels are different, but the processing of the planets is basically the same.
For instance, the settings I used for Uranus were; gain 400 and shutter speed 50 ms (giving me 20fps), Neptune has the same shutter speed but the gain was 500, both captured for 5 minutes. For comparison, with Jupiter I normally use a shutter speed of 6.66ms (150 fps), Mars is 4 ms (250 fps) and Saturn is 10 ms (100 fps).
Stacked in AS!3, sharpened (usually) in Registax, post processing in Photoshop. The moons are extracted using the levels tool in Photoshop, in the same way I extracted the moons of Saturn here. http://www.iceinspace.com.au/forum/s...d.php?t=186994
Andrew,
Thanks for your response and kind sharing of your technique, quite scientific the way you reveal the moon shapes which gives the overall planet scene interesting context (I'll be keen to have a go now). This hobby has a lot of small tricks to learn which makes it so interesting.
Cheers Andrew,
