Wesley's Tool-Box

The International Space Station was to make a very close pass to Rigel, one of the brightest stars making up the Orion constellation, last Saturday evening where I live. The separation at the closest point was around 0.055°, making it look like the space station passing right over the star to the naked eye. Instead of manual tracking, I decided to fix the telescope on Rigel and record the pass with iPhone X's 4K 60fps video mode. A total of 50 consecutive frames captured the rapid movement. The windy condition, coupled with relatively low angle (35.6°) blurred the results a lot, so I should try this technique again at a higher angle.


Here's the rotated video of the pass, once at the original speed and once at the slow speed.

Telescope: Celestron NexStar 6SE + X-Cel LX 9mm eyepiece
Device: iPhone X (afocal)
Settings: 28mm - ISO 880 - 1/1500s - f/1.8
Filters: None
Date/Time: 2018-03-24 20:00:59 KST
Location: Naju, Korea

The first total lunar eclipse of this year was an interesting one in that it was a so-called "Super Blue Blood Moon". The visible size is the largest, so it's a Supermoon. It's the second full Moon of the month, so it's a Blue Moon. The Moon hidden behind the Earth's shadow during the eclipse looks reddish, so it's a Blood Moon. This was the first such occurrence seen in Korea since December 1982, so it's not common.

The sky was pretty cloudy all the way to the late evening yesterday, so I had nearly given up on seeing it. But I was in luck and the clouds had started clearing up soon after the eclipse had started. So I hurriedly got my Sony camera and a tripod out to catch the event. It had only half a charge left, but I managed to photograph the progress for two hours, including the deepest point occurring around 22:29. I think it turned out fine - here's the composite photo showing the progress of the eclipse in 5-minute interval.

Device: Sony A5000 + SELP1650 (E PZ 16–50 mm F3.5–5.6 OSS)
Settings: 50mm - ISO 100 - 2s - f/5.6
Filters: None
Time: 2018-01-31 21:40-23:40 KST
Location: Naju, Korea

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

Much has been talked about this year's so-called Supermoon owing to the fact that it's the largest since January 26, 1948 and won't be surpassed until November 25, 2034. Closest approach was made on 22:52 KST on November 14 at a distance of 356,509km, about 28,000km closer than average. The resulting difference is hardly noticeable to the naked eye, but is nevertheless a nice occasion to look at the Moon again. Sadly, heavy clouds hid the Moon entirely at that time, so I saw the Moon the next evening, about 20 hours later and used the telephoto lens on the iPhone 7 Plus to take a photo of it. This is perhaps the most detailed shot of the Moon taken using only an iPhone's native camera module.

Device: iPhone 7 Plus
Settings: 56mm - ISO 20 - 1/60s - f/2.8
Filters: None
Time: 2016-11-15 19:06 KST
Location: Naju, Korea

In Korea or Japan, loud camera shutter sounds from smartphones are a fact of life due to the voluntary standards for the camera-equipped cellphones meant to ease privacy concerns. Issues had already been raised as far back as 2001 in Japan and Korean government started taking action in 2003. These standards call for a mandatory shutter sound of certain loudness even in silent mode. In Korea, sound level is set to be between 60 and 68dBA.

Note that this is not mandated by law in either countries, so there is no legal repercussion for not honouring the standards. Still, it poses an annoyance in many legitimate circumstances, something that users in other countries would never encounter. Imagine that the phone will make a loud sound whenever you take a photo or a screenshot(!) even in silent mode. There are 3rd party camera apps that try to avoid the sound, but for the screenshots you would ultimately need a system-level hack. This means jailbreaking or finding an obscure bug/feature.

I noticed that this problem has been exacerbated on the iPhone 7 series because it is using two speakers instead of one. You'll now get to hear the noisy shutter sound even louder, in stereo. To get an objective picture of the situation, I brought out my iPhone collection for a round of sound level measurement for the camera shutter sound. Here's how they stacked up.


The test was done by measuring the sound using the "Decibel 10th" app on the iPad Pro 9.7". Tested iPhone was 40cm(16") away from the iPad's microphone. To human ears, an increase of 10dB is felt as the sound being twice as loud. This means that the integrated speaker got roughly two times louder since iPhone 5 onwards. Incidentally, this would've been necessary to meet the aforementioned Korean standards. The 60dB level must be attained at a distance of 1m(3.28'), and there is a decrease of 8dB for moving from 40cm to 1m. Taken together, it becomes obvious that the iPhone 4S and earlier models wouldn't be loud enough.

And as expected, iPhone 7 I bought in Japan was the loudest, even though the second speaker was facing away from the iPad's microphone. One consolation is that the sound heard by the subject isn't much louder than before; you only hear it as being much louder because the second speaker is facing you.

Meanwhile, the iPhones bought in the United States turned out to be relatively quieter even when the volume was set to the loudest. In fact, my iPhone 7 Plus had a very quiet shutter sound even though music playing on it was quite loud in contrast. This shows that Apple is intentionally boosting the speaker output beyond normal levels when the shutter sound is made on the Korean and Japanese models. It would be difficult for those who haven't used these models to realize how loud they are.

If you want to hear the difference for yourself, here's the video of the test that the results are from. If anyone had been wondering why I still try to get iPhones from the United States, this should be the answer.