Category: Post

Fun with digital photography

Recently I’ve been diving into High Dynamic Range (HDR) photography. Initially I used Bracketeer to combine three photos that had been taken with different exposure (-2, 0, +2 stops). But very quickly I became unsatisfied with the output from Bracketeer. After a little research, it turns out Bracketeer only fuse photos with different exposures. Whereas other HDR software also perform tone mapping. After listening to a TWiP podcast about HDR and read through the HDR tutorial by Trey Ratcliff, I decided to try Photomatix Pro last week to see what different result I would get.

To demostrate the difference between Bracketeer and Photomatix, here are two identical photos processed by each software with the original exposure on the left:

Original
Bracketeer
Photomatix

As you can see, the result from Photomatix is so much more natural looking (though it can also produce extremely psychadelic version) than Bracketeer. And more importantly, I get to this very good photo very easily, whereas the options in Bracketeer are extremely technical and confusing.

Both are commercial software with Bracketeer a little bit less expensive than Photomatix. But judging from the output quality, I would thoroughly recommend going straight to Photomatix if you want to experiment with HDR.

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Extending iPhone battery life

Since my first iPhone, I’ve never had any issue with its battery life. As long as I get access to the charger by the end of the work day the battery life on the iPhone 2G or 3G have been perfectly adequate. That is until I started working on a project down in Atlanta and my weekly commute now extends to around 6-8 hours, depending on flight delays.

I began looking for battery extender for my iPhone. Initially I wanted a battery extender that can charge the iPhone 3G and 3GS, as well as possibly the Kindle. This means the ability to attach different cables to the battery. Also the ‘green’ side of me wanted a solar charging battery so that it’d be possible to charge the battery up using solar energy alone.

Unfortunately after perusing iLounge’s extensive list of battery extender reviews, it was pretty obvious that there weren’t any battery out there that would satisfy my initial list of requirements. The closest one is the IceTECH Solar i9005. With its large solar panel, large battery capacity (2500 mAh), and large collection of connector tips, it would be ideal. The only issue is it doesn’t currently support the iPhone 3GS, as Apple in its infinite wisdom has changed something with regard to charging on the 3GS.

So the search was back to regular battery extender. There are plenty of options out there but none of them really excite me. At least not at the price they are charging for. That is until I came across MonoPrice’s iPhone backup battery. With a rather large capacity (2200 mAh *) and very affordable price (~$15, depending on quantity purchased), it is perfect.

It arrived two weeks ago and I have so far used it twice. From about 10-15% charge in the iPhone, it would take about two hours to fully charge the phone from the backup battery. During that time, I was able to continue to use the iPhone with podcast playing in the background while online twittering and browsing. The only thing that is annoying is the ‘cyclon’-like blue LEDs in the front which move from left to right during the charging process (both from main to battery, and battery to phone). They are very bright and very distracting while using the phone with the battery attached, especially in a dark backseat of a taxi! To charge the backup battery, simply plug the iPhone cable to the bottom of the battery and charge it just like the phone. Unfortunately the battery does not pass the data through to the phone so you can’t sync with iTunes while charging both the phone and the battery.

But overall, the MonoPrice iPhone backup battery is priced just right and perform as advertised. High recommended if you are looking for a simple backup battery for your iPhone.

* For comparison, iPhone 3G battery capacity is 1150 mAh which means the MonoPrice battery can potentially charge the iPhone from 10-15% charge to full twice!

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UITableView scrolling performance gotcha

After a few months of .NET reporting/SSIS development work, I’m back to an iPhone project this week. One enhancement I added yesterday was a better formatted table section title in a UITableView. Before, the section title is either a bunch of unformatted (also incorrectly by locale) dates (e.g. 2009-09-30), or times (e.g. 14:58) straight from the data source. The enhancement/bug fix is to format the date or time to be locale aware so the title would either be “Wed Sep, 30 2009” or “2:58 PM” if you are in the US.

Pretty straightforward I thought, and after a couple of trips to NSDateFormatter and use the output in UITableView’s titleForHeaderInSection:section method, it was all working very well in the simulator. That was until I put the app onto my iPhone for some real in-device testing.

The scrolling performance in the table was horrible! My first thought was that it had to do with the background view I added to the custom table cell view for colouring the table cell background. But after nearly an hour of debugging through the code I still couldn’t find anything wrong.

Turns out that the titleForHeaderInSection:section method is not just called once per controller instantiation. It is called once per table cell display!

Once I moved the code to format the section title into viewDidLoad and cached a copy of the nicely formatted titles in an array, the scrolling is back to normal speed.

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QotD: The One Historical Event I’d Like to Witness

If you could have personally witnessed one event in history, which one would you want to have seen?

July 16, 1969 Landing of Apollo 11 on the Moon.

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