Wesley's Tool-Box

Just after taking photos of Saturn last Thursday, I could see that Mars was right next to it, so I decided to point my camera at it, as well. This would be the first time I took photographs of Mars.

Closest approach of Mars to Earth for this year would happen in about a month (April 14), but it wouldn't be quite as close as some of the years, so it would look rather small - it would be 60% that of August 27, 2003 and 62% that of July 31, 2018. Still, I'll try to take some photos when that happens.

Device: Canon SX50 HS
Settings: 1200mm (2x enlarged) - ISO 80 - 1/125s - f/6.5
Filters: None
Time: 2014-03-06 06:32 KST
Location: Suwon, Korea
14 photos stacked with RegiStax 6.1.0.8

Saturn is the first planet I photographed with my Canon SX50 HS back in June 2013. The rings made it clear that I was shooting a planet, and served as a great first target. Since then, I got around to taking photos of other planets, satellites (natural and artificial), and stars.

In the meantime, Saturn was beginning to set too early in the sky, so I was no longer able to take new photos of the planet for several months. Now it rises in the middle of the night, up in the sky until dawn. I woke up this morning slightly early, and saw Saturn weakly shining against the brightening southern sky. I quickly set up my camera and got some shots.

The rings are still quite nicely visible around the planet. Compared to last year, Saturn seems to be leaning a bit more, making the rings look more like ears.

Device: Canon SX50 HS
Settings: 1200mm (2x enlarged) - ISO 160 - 1/30s - f/6.5
Filters: None
Time: 2014-03-06 06:27 KST
Location: Suwon, Korea
29 photos stacked with RegiStax 6.1.0.8

This is a recording of the flare from Iridium 20 satellite over at Yatap subway station in Seongnam.

Device: iPhone 5S
Settings: 30mm - ISO 1250 - 1/15s - f/2.2
Filters: None
Time: 2014-01-28 19:25 KST
Location: Seongnam, Korea

Sun is measured to be the most perfectly round sphere occurring in nature. But as the Sun sets over the horizon, it looks more "squished" than usual due to atmospheric refraction. This photo was taken when the Sun's altitude was merely 3.27 degrees.

You can still see the sunspots just fine - AR11960 (top; "sunspot 1960") and AR11959 (bottom; "sunspot 1959") are visible at the lower area. The light blemish at the lower right edge is the AR11957.

Device: Canon SX50 HS
Settings: 1200mm - ISO 80 - 1/40s - f/6.5
Filters: Baader AstroSolar Safety Film
Time: 2014-01-26 17:25 KST
Location: Suwon, Korea
79 photos stacked with RegiStax 6.1.0.8

I've been using my Canon SX50 HS superzoom camera almost exclusively as an astrophotography machine since middle of last year. The 50x zoom is enough to make many of the planets show up as disks rather than spots, so it feels like having a compact telescope with integrated camera. At full zoom, the settings are at 1200mm, f/6.5, and ISO is set to 80 for best quality. Jupiter shots are usually taken at around 1/100 to 1/250s shutter speed (it was 1/160s here), while bright Venus shots can go up to 1/1000s.

Of course, even such massive zoom by camera standards don't make the planetary disk very big. two biggest examples are Jupiter, which goes up to about 32 pixels wide, and Venus, about 41 pixels wide. So getting good details from a single shot is difficult. I have to apply some techniques used by the astrophotography community to enhance the results.

The big helper is undoubtedly RegiStax, which does both stacking and wavelet processing. The stacking averages the multiple photos of the same object, which preserves the details while reducing noise. RegiStax doesn't simply stack the photos, though. They are aligned and only the ones with good quality are picked out for stacking, which improves the quality even further.

In this Jupiter example, I took 131 photos of the planet, out of which 41 of them were picked by RegiStax for stacking. Compared to the grainy photos originally taken by the camera, the stacked image is much more cleaner and smoother. But the cloud features are soft and hard to make out. This is where wavelet processing comes in.

Wavelet processing can be used to amplify the little details in the photos and make them stand out. After making some adjustments on the strength of each wavelet layers, the cloud features became more distinct. There's a ripple in the lower part, and magnifying the processed photo by 200% shows that this is the Great Red Spot (GRS). Rotating the photo (by 54 degrees in this case) makes the planet look "upright".

And this is how I currently process the planetary photos.

Settings: 1200mm - ISO 80 - 1/160s - f/6.5
Time: 2014-01-19 02:57 KST
Location: Suwon, Korea