Wesley's Tool-Box

Jupiter and its four major satellites (Galilean moons) are good targets for time lapse photography because of the relatively rapid movement. The rotational period of the planet is slightly less than 10 hours, and Io, the innermost of the Galilean moons, orbits the planet in about 42.5 hours. Under good conditions, these things become noticeable over a span of just about an hour.

Shortly after midnight of April 20, 2018, Io came out from behind Jupiter on the left side, while the Great Red Spot was moving towards the back of the planet on the right side after being in the center. These were all captured on my camera as I took 597 photos of the Jovian system over a period of 100 minutes between midnight and 01:40AM. The photos were then stacked and processed in 1-minute intervals (6 photos on average), like the one you see above, then put together into video as you see below.


I think it shows the dynamics of these celestial objects quite well. Now that I have a good grasp of the workflow for making a planetary animation, I should be able to make a similar one for Mars when it approaches Earth close enough to be seen as half the apparent size of Jupiter next July. Before wrapping up, here's a bonus picture of the Jovian system that I took just after photographing the Sombrero Galaxy. You can actually see Io casting a tiny shadow on Jupiter. I thought I would never see that sort of thing on my telescope.


Telescope: Celestron NexStar 6SE
Device: Sony A5000 (prime focus)
Settings: (1500mm) - ISO 100 - 1/15s(#1), 1/20s(#2) - (f/10)
Filters: Baader Moon & Skyglow
Time: 2018-04-20 00:00 ~ 01:40(#1), 2018-04-19 01:03(#2) KST
Location: Naju, Korea
597(#1), 6(#2) photos processed with PIPP 2.5.6 and RegiStax 6.1.0.8

It's been about two years since I did astrophotography with my Celestron telescope. When I finally took it out of storage to take the photos of ISS recently, I noticed that the shots weren't as clear as I expected. The same problem came up as I tried to take photos of the Orion Nebula yesterday, and I realized that the collimation of the telescope was significantly off. After about an hour of fiddling, the problem was fixed and I was able to see the bands of Jupiter and the Cassini Division on Saturn again. It looks like I'm good to go for the next few months of observation, including the closest approach of Mars on July 31. Here are the photos of the two planets in the order of original (from 4K 60fps recording), stacked, and wavelet processed results. Resolution was roughly 0.32"/pixel due to the iPhone X having slightly wider lens than iPhone 6S Plus.



Telescope: Celestron NexStar 6SE + X-Cel LX 9mm eyepiece
Device: iPhone X (afocal)
Settings: 28mm - ISO 50 (Jupiter) / 250 (Saturn) - 1/60s - f/1.8
Filters: None
Date/Time: 2018-04-08 05:18 (Jupiter) / 05:30 (Saturn) KST
Location: Naju, Korea
100 (Jupiter) / 46 (Saturn) photos stacked with PIPP 2.5.6 and RegiStax 6.1.0.8

As I dropped by Gwangju to catch a movie (I'll be posting a comic tomorrow), the western sky was adorned with an alignment of some of the bright bodies of the solar system as seen from the Earth - the Moon, Mars, and Venus. The occurrence was relatively well-publicized, but I forgot to carry a dedicated camera tonight. Luckily, the telephoto lens of the iPhone 7 Plus pulled through and I was able to capture this sight over the neighbourhood just before Venus dropped behind the buildings.

Device: iPhone 7 Plus
Settings: 56mm - ISO 1000 - 1/12s - f/2.8
Filters: None
Time: 2017-02-01 21:12 KST
Location: Gwangju, Korea

A few hours after walking in the rain to see a movie yesterday, I was getting ready to sleep. Then I noticed that the sky was crystal clear, something I haven't seen in more than nearly two weeks (or three, in the night). Not to pass up this opportunity, I got my camera out. With so many stars visible, I wondered if the Milky Way Galaxy could be captured even with all the lights from the apartment buildings nearby.

After a few tries, it became clear that indeed it could be done, if somewhat faintly. Adjusting the levels, curves, and contrast brought out further details. Individual colour channels were untouched, yet the sky showed a very nice gradient. This may be an unintended affect of the light pollution near the horizon and I like how it turned out.

Device: Sony A5000 + SELP1650 (E PZ 16–50 mm F3.5–5.6 OSS)
Settings: 16mm - ISO 2000 - 20s - f/3.5
Filters: None
Time: 2016-07-08 00:44 KST
Location: Naju, Korea

I used the Opteka 2x teleconverter lens for astrophotography for the first time when I took another series of photos of the planets two days ago. This is supposed to be used with telephoto mirror lenses, but that's basically what my telescope is as well and I hoped it would be usable here. Test shots during the day came out alright, maintaining better contrast than the 2.5x Barlow lens I had been using. As you can see here, it performs reasonably well in the night, too.

I didn't originally intend to photograph the Saturnian satellites because they are quite dimmer than the Jovian ones. The four biggest Jovian satellites have apparent brightness in the magnitude 5 range, while the biggest and brightest Saturnian satellite, Titan, is around magnitude 8. The three largest after Titan are of magnitude 10. That's why I didn't take separate photos with longer exposure. Even so, post-processing the background area revealed the dim satellites. I noted their relative positions with the caption. Dione may be barely visible on on well-tuned screens.

Telescope: Celestron NexStar 6SE + Opteka 2x Teleconverter
Device: Sony A5000 (prime focus)
Settings: (3000mm) - ISO 100 - 1/3s - (f/10)
Filters: None
Time: 2016-06-15 00:12-00:13 KST
Location: Naju, Korea
26 photos stacked with PIPP 2.5.6 and RegiStax 6.1.0.8

Yesterday's sky was full of light clouds that became thicker as times passed. It was just enough see very bright stars and planets, so I decided to check how large the planets would appear with my old Tamron 270mm lens on my Sony A5000 camera. Jupiter came out to be about 11 pixels wide, or about 3.3 arc seconds per pixel. I then attached the camera to the telescope and saw that the planet was about 64 pixel wide, or about 0.56 arc seconds per pixel. This is more or less in line with the 1500mm focal length.

Since Jupiter was still somewhat "photographable" even with the cloud cover, I decided to take some more photos and stacked them to produce this nice result with all four Galilean satellites in view. The last time I took a photo like this was three years ago.

Telescope: Celestron NexStar 6SE
Device: Sony A5000 (prime focus)
Settings: (1500mm) - ISO 100 - 1/2s - (f/10)
Filters: None
Time: 2016-06-10 21:48 KST
Location: Naju, Korea
20 photos stacked with PIPP 2.5.6 and RegiStax 6.1.0.8

Mars rotates once every 24 hours and 37 minutes, so the look of the planet would visibly change as you keep an eye on the planet during the night. Owing to the fact that Mars is at its closest to Earth in more than ten years as I write this, this phenomenon had become relatively easy to photograph with my equipment. In fact, yesterday's post already illustrated this point.

However, I wanted to see if this could be made into an animation. So I managed to take photos of Mars in 30-minute intervals in the span of 4 hours. I wanted to stay up longer, but practical considerations like sleep and humidity prevailed. As you can see at the top, I ended up with a total of eight frames after post-processing nearly 3,000 burst mode photos taken with my iPhone 6S Plus mounted on the telescope. They were then put together into GIF animation that you see on the left.

The frames preserve the 2x digital zoom that I used while taking the photos because it allows you to discern the major features of Mars easier. The dark spot that sticks out on the right side of the planet in the first four frames is Syrtis Major Planum. The brighter area at the center of the planet in all the frames is Arabia Terra. Left side of the dark area just below the Arabia Terra is Meridiani Planum, where the Opportunity rover (MER-B) is currently operating (for more than 12 Earth years as of this writing). The dark area to the left of Arabia Terra visible on the last frame is Acidalia Planitia.

Telescope: Celestron NexStar 6SE + X-Cel LX 9mm eyepiece
Device: iPhone 6S Plus (afocal, 29mm - f/2.2 fixed)
Filters: Baader Moon & Skyglow
Location: Naju, Korea (time in KST)
Stacked with PIPP 2.5.6 and RegiStax 6.1.0.8

#1 (114 photos): ISO 200 - 1/25s @ 2016-05-30 22:10-22:11
#2 (116 photos): ISO 125 - 1/60s @ 2016-05-30 22:44-22:45
#3 (142 photos): ISO 100 - 1/50s @ 2016-05-30 23:12
#4 (130 photos): ISO 100 - 1/50s @ 2016-05-30 23:42
#5 (103 photos): ISO 100 - 1/50s @ 2016-05-31 00:10-00:11
#6 (106 photos): ISO 100 - 1/50s @ 2016-05-31 00:39-00:40
#7 (85 photos): ISO 100 - 1/50s @ 2016-05-31 01:09-01:10
#8 (118 photos): ISO 100 - 1/40s @ 2016-05-31 01:40