Latest Comic : Monday, December 10. 2018

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Watching a rocket launch: Nuri(KSLV-II) TLV

Nuri TLV at T+34s - soaring into space with "대한민국" (Republic of Korea) on the right-hand side

Republic of Korea (South Korea) has been developing a fully indigenous launch vehicle called Nuri, also known as KSLV-II, after the joint development of KSLV-I (Naro) with Russia was complete five years ago. The key piece of this technology is the KARI 75-Ton rocket engine, of which four of them would be used on the first stage and one on the second stage. To see that the engine actually can launch itself, a single-engine single-stage version of the rocket, called TLV (Test Launch Vehicle) was created. It was launched successfully today at 16:00 sharp, Korean Standard Time, and I was able to record it fully, as you can see here.

Watching the launch from across the sea with Nikon P1000 set to maximum zoom

Originally slated for October 25, the launch was delayed to today, November 28, 2018. But I was still able to take half a day off from work to see this for myself. I headed to a nice lookout spot in Naenaro Island, only about 7km from the launch site, which was not quite as obscure as I initially thought - there were already dozens of people there when I arrived, including a TV crew. Luckily, there was still a spot for me to set up my Nikon P1000 camera for observation and recording.

The distance was too far for the naked eye to properly see the rocket. Only the fiery dot could be seen rising up to the sky. But the P1000's powerful zoom was more than good enough to capture the sight in its full glory. I was able to track the rocket with relative ease using the Olympus EE-1 dot sight attached to the camera. For the full video recording, see below.


For some more frame captures, please read on.
Continue reading "Watching a rocket launch: Nuri(KSLV-II) TLV"

Nikon P1000 observes ISS-Sun transit

Nikon CoolPix P1000 observes the Sun next to Celestron NexStar 6SE telescope

Encouraged with the results from the previous observation, I took the Nikon P1000 outside during the day to take the photos of the ISS crossing in front of the Sun. Last time I was able to see the transit at home was three and a half years ago. I also got my Celestron telescope out as a backup in case any one of the equipment failed to record the phenomenon. The camera needed a solar filter like the telescope, so I bought an ND100000 glass filter online for US$40 that provided the same amount of light reduction.

Full-resolution composite of the ISS passing in front of the Sun on November 3, 2018 (click for the full photo)

Although the P1000 has burst mode, it can only take seven photos in a span of a second. The window of opportunity was too narrow, so instead of taking the risk I used the 4K 30fps video capability instead. It would sacrifice image quality, but I was sure to get the shot if the frame and focus were right. And sure enough, the transit was captured successfully as you see above.

Stacked image of the ISS shows the details

The result may not be not quite as sharp as using a telescope, but much of the features of the space station were distinguishable. Perhaps I should try the burst mode the next time I get the opportunity to see if that makes a difference.

Device: Nikon P1000
Settings: 3000mm - ISO 400 - 1/500s - f/8
Filters: ICE N100000 (Neutral Density 16.5 Stop)
Time: 2018-11-03 10:48:02 KST
Location: Naju, Korea
17 photos processed with Pixelmator and RegiStax 6.1.0.8

Adventures in fixing broken Korean text in MySQL DB

The Tool-Box.info website has been running on the Apache - PHP - MySQL (APM) solution for the past 13 years. Each component has been constantly upgraded over the years, and recently I decided to update MySQL from 5.7 to 8.0. Once I managed to migrate the database to the new version, I discovered that all the Korean texts on the website came out broken. This was a sign of mismatched character set, so I looked for the exact cause.

First, I rolled back to 5.7 and checked what character sets were being used, using the following SQL query:
show variables like 'char%';

Sure enough, "character_set_database" and "character_set_server" were set to "latin1". Upon checking the database and the tables that contain the website data, their character sets were all set to "latin1_swedish_ci", the default choice. All the Korean texts were being saved to the database in Latin1 format from the very beginning. It got converted into UTF-8 as it was passed to the output, so it looked normal when viewed through a web page. But if you looked directly into the database, it came out broken. MySQL 8.0 apparently decided to output the text in its saved form, unlike 5.7, hence the problem.

The solution proposed by many of the Korean blogs that had a similar problem was to alter the character set of the affected databases and tables in the following manner:
ALTER DATABASE data_database CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci;

ALTER TABLE data_table DEFAULT CHARSET=utf8mb4;

ALTER TABLE data_table MODIFY COLUMN title VARCHAR(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;

And also, add the following lines under [mysqld] in the MySQL configuration file (my.cnf):
collation-server = utf8_unicode_ci
character-set-server = utf8

Sadly, all this did not help one bit. Upon further analysis, I arrived at the conclusion that the underlying data was still in "broken" form even if the settings had the character set changed. The data itself has to be rewritten in UTF-8, so I needed to dump the database and reload it in the correct character set. First, the dump:
mysqldump -u root -p --default-character-set=latin1 data_database > dump.sql

The "default-character-set" flag was set to "latin1" to ensure that the data is dumped in its originally saved character set. In the dumped file, I changed all the "latin1" strings into "utf8mb4".

Now I simply had to restore it back, but the "Specified key was too long; max key length is 1000 bytes" error prevented me from restoring some of the tables. I tracked the problem down to the limitation of the MyISAM database type. Because the "VARCHAR" data type for a column needs 3 times more space for UTF-8 than Latin1, the character set change caused the key length to exceed the 1000-byte limit. With InnoDB database type, it was 3072 bytes by default since MySQL 5.7.7.

Because of this, I changed the database type mentioned in the file from MyISAM to InnoDB. So why was it set to MyISAM in the first place? It was because Full-text index was not available for InnoDB at the time of the database creation. It was enabled in 2011 with MySQL 5.6.

With both the database type and character set changed in the dump file, I restored the database like this:
mysql -u root -p --default-character-set=utf8mb4 data_database < dump.sql

I could now see that all the Korean text appeared correctly in the database. It would also look right on the website if I kept the changes to the my.cnf file mentioned earlier. Finally, I migrated the database to MySQL 8.0 again, and ran the "mysql_upgrade" command. Everything was working as intended, and I no longer needed the changes to the my.cnf, so those were removed.

Long story short, initial database settings from 13 years ago almost held me back from upgrading to the newest MySQL version, but all of them are now fixed.
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Tracking the ISS with Nikon P1000

Int'l Space Station captured by Nikon P1000 on October 27, 2018

Next target I've been eyeing to take some photos of using the powerful zoom provided by the Nikon CoolPix P1000 camera was the International Space Station. Although it's a fast-moving target, I have experience with other equipment and the P1000's zoom should be sufficient enough to let me distinguish major features under ideal conditions, similar to the photos I took using a telescope. One such pass happened on October 26, coming in as close as 410km, but the thick clouds prevented me from taking the shots. Luckily, a slightly worse backup opportunity (closest approach of 572km) happened just a day after and I made the best of it - what you see above is the result.

iPhone 5S was used to help track the ISS as the P1000 took photos

As it was the case with SX50 HS, tracking the station is nearly impossible with just the integrated screens on the camera. So I enlisted the help of an iPhone mounted on the camera's hot shoe. It was very effective and I was able to take an unbroken sequence of the space station for more than a minute, until it went out of my view. If you want to see the whole thing, watch the video below. I think it was good for a first try with a new camera. More opportunities are to follow in the coming weeks, so stay tuned.



Device: Nikon P1000
Settings: 3000mm - ISO 100 - 1/320s - f/8
Filters: None
Time: 2018-10-27 05:29-05:31 KST
Location: Naju, Korea
78 photos processed with PIPP 2.5.9 and RegiStax 6.1.0.8
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Planetary observation with Nikon P1000

Saturn and Mars on October 19, 2018

I'm getting the hang of photographing the planets with P1000 after some practice. Jupiter sets below the horizon too early these days, so I targeted Saturn and Mars. Using the Moon as the reference for the manual focus (actual setting seems to vary up to ten dial ticks by the daily conditions) and turning off the vibration reduction (better to let the tripod stabilize on its own), I was able to take several photos for processing. Discernible in the results are the prominent differences in the surface colours of Mars, as well as the Cassini Division on the rings of Saturn.

Device: Nikon P1000
Settings: 3000mm - (Saturn: ISO 200 - 1/40s / Mars: ISO 100 - 1/160s) - f/8
Filters: None
Time: 2018-10-19 (Saturn: 19:15 / Mars: 20:50) KST
Location: Naju, Korea
(Saturn: 9 / Mars: 11) photos processed with PIPP 2.5.9 and RegiStax 6.1.0.8
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