Jupiter & Saturn, optimistic imaging

[turfpit]

Captured 20th Dec 2020. Shot into Manchester (UK) sky glow with elevation around 5°. Atmosphere boiling, green channel tortured by diffraction. A big ask to capture bright Jupiter and dim Saturn in one FOV.

Celestron C8 with 0.5x reducer, JMI motorised focuser, ZWO ASI 120MC, IR cut filter. 8-bit RAW, SER, 27fps. Best 20% of 2000 frames in Autostakkert. GIMP for some pixel mangling.

2020-12-20-1720_1_lapl6_ap4_conv.jpg (31.34 KiB) Viewed 1830 times

Capture in progress:

Jupiter-Saturn-capture.JPG (84.7 KiB) Viewed 1830 times

Over exposed showing several moons:

Jupiter-Saturn-over-exposed.JPG (88.93 KiB) Viewed 1830 times

Capture file viewed in SER Player, notice the excess green channel:

Jupiter-Saturn-SER-Player.JPG (30.24 KiB) Viewed 1830 times

Dave

[oopfan]

As my stepmother would say: "It was one of my lesser successes" which revealed her optimism.

An excellent showing for 5 degrees above the horizon!

Brian

[turfpit]

Thanks Brian, a bit of a tester but I managed to capture the rings. If I was imaging those 2 planets individually, the Saturn exposure would be at least double the Jupiter exposure. Autostakkert offered me 4 alignment points on Jupiter.

Dave

[oopfan]

I like the "well-exposed" shot of Jupiter, it's moons, and Saturn. It really shows how close they are.

Sometimes we can't make pretty pictures, but there is always valuable information in there. This hobby is even more enjoyable when we recognize that there is science in every frame we take.

Brian

[admin]

Hi,

nice work Dave!

I seem to recall playing around in the past and being able to see Jupiter in daylight as long as you get the scope aligned in order to find it. I wonder if there's value in trying to capture this pair before sunset when there are a bit higher in the sky. Colour imaging might be a challenge, but a mono sensor with a planet killer filter that will cut out the blue might work quite well.

Cheers, Robin

[turfpit]

Thanks Robin. If I get another weather window I will try this again in the failing light with my IR685 filter and QHY5lII-M. The mount is on a pier so is roughly polar aligned (although not an issue for a 2,000 frame capture). I am fast running out of sky though.

Dave

[admin]

Yes, the weather hasn't been kind to us here UK. I popped my head outside at about 5 PM and it was raining nicely, so no chance of seeing the conjunction here this evening.

Hope you had better luck,

Cheers, Robin

[RonAM]

Nice work Dave. Great initiative & drive to give it a go at 5-deg elevation. Here at 42-deg N location the planets were at 23-deg elevation at 1600 local time, setting fast to 17-deg 1-hr later. I set up my scope before sunset and did a 2-star alignment of my Starmaster dob on Polaris and Altair. I used cell phone compass and Clinometer apps to set the altitude and azimuth of my scope for each alignment star at their respective 1530 local time locations. This is a case where an equatorial pier and pre-aligned scope would have been nice to have, but this process actually worked. After the sun set and I could see the planets in my finder they were within a half degree of center. Results at 20-deg elevation were acceptable, not great. For processing the SER video I first tried Autostakkert but later found it was better to first use PIPP to preselect the best 30-50 frames of the 250-1000 taken, then use Autostakkert to stack those best SER frames from PIPP, then on to Registax 6 wavelets to sharpen the stacked TIFF image. It is wonderful to have such capable equipment and software like SharpCap and these other applications. Due to our hazy skies and nearby solar glare through that haze, the planets were not visible in the scope until 1615 local time and were not visible to the eye until after I completed my session at 1700.

All the best, Ron

[turfpit]

Thanks Ron. I had the added challenge of capturing into the skyglow of a large city plus 11mph winds.

At 53°N, Jupiter & Saturn have been hard targets this year. I think things start to improve in 2021. Using PIPP to pre-process frames for stacking in Autostakkert is a good idea as it can help with image centering/cropping and image stabilisation. viewtopic.php?f=35&t=2773

Hope you have a good Christmas and New Year.

Dave

[RonAM]

Merry Christmas Dave and to all on the site.
I’m not a programmer, but it seems PIPP does a better job selecting best frames with turbulent image data than Autostakkert does. They seem to give similar results if there is less turbulence. After PIPP I used Autostakkert to select and stack 50% best frames. The quality graph after PIPP was much better than not using it. Without PIPP the Autostakkert quality graph showed 10-15% usable frames, and the stack of those was not as good as first using PIPP.

Clear skies and stay well

Ron