Entries tagged as astronomy

Processing small photos of the planets

Enhancing Jupiter shots from SX50 HS

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
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Smallest full Moon in 12 centuries

This Moon is smaller, but not tiny

According to CalSky, tonight's Moon looks the smallest since October 28, 817. That's 1197 years ago. Next smaller full Moon will show up 140 years, on December 19, 2154, so for pretty much everyone reading this blog, this is the smallest one you'll see on Earth in their lifetime. Go out and enjoy the view while you can.

This was taken with my iPhone 5S through a hazy night sky on 19:35 KST via Cortex Camera.
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Phases of Venus

More than 4 months of observing Venus

Here is all my recent observations of Venus through Canon SX50 HS in one picture. I think it shows pretty well how Venus dramatically approaches Earth while being in the inner orbit. The last six observations have been posted in the blog before:

[2013-10-30] [2013-11-17] [2013-11-30]
[2013-12-07] [2013-12-21] [2014-01-04]

The first two didn't look much on their own, so I didn't make an entry about them when they were photographed, but they make for a nice comparison, so I included them here now.
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Iridium 42 satellite flare


The Iridium 42 featured in today's "The Toon-Box" was a frame from the series of burst shots I made with iPhone 5S. You can see the video of these shots as this YouTube video.

Device: iPhone 5S
Settings: 30mm - ISO 320 - 1/15s - f/2.2
Filters: None
Time: 2014-01-09 17:55 KST
Location: Seoul, Korea
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Today's "The Toon-Box"

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