HDR Photography

Over the weekend I bought myself a new SD card for my Canon SD700 IS camera for the expressed purpose of having a little fun with it. For those of you who don't know me, when I use the word ‘fun’ in the context of something electronic, it means that I'm planning to hack it. I have always enjoyed hacking electronic things to make them more useful, like getting my iPhone to work with the t-Mobile network, and the camera is a perfect project.

I've had the Canon SD700 IS for a few years now and while I love it for it's near instant start-up (less than 1.5 seconds from power on to taking a photo) I have always wished that the camera allowed me more control over how it shoots photos. Capabilities like being able to shoot long exposure photos or bracketing for high dynamic range photos really interest me, but cameras that offer these features out of the box are too expensive for my tastes.

The worst thing about these lack of features is that the camera hardware is capable of so much more than the software that it ships with allows. The shutter speed limit imposed by the default software it ships with is 80% slower than what the camera is capable of. I'm sure that you've heard the myth that we only use 20% of our brain; in the case of the Canon PowerShot cameras they only offer us 20% of the capabilities.

What can we do to address these limitations? Enter the open-source Canon CHDK firmware.

The CHDK, or Canon Hacker’s Development Kit, is a new firmware upgrade for the Canon cameras that allow you to do loads more with your PowerShot camera. You can set it up as a motion sensitive capture device, set the exposure to last up to 65 seconds and shoot in RAW mode (which offers far more information from the CCDs in the file format). This is photographic feature gold. It takes a basic point-and-shoot Canon digital camera and turns it into the feature equivalent of a top of the line digital camera.

On Sunday I loaded the software onto the new SD card and played around a bit with it. The first trick was stripping out the 'quarantine' flag that downloaded files get in MacOS X, because it would not run with the flag in place. This was accomplished with a bit of UNIX command line fun, and once the card was re-inserted, the new software loaded up fine.

The first new feature that I explored was creating high dynamic range photos. HDR photos use the tonal details from different exposures and merge them to create a composite photo with a much wider dynamic range than a traditional camera can take. This allows you to bing out the details in shadows and bright areas without over or under-exposing the image. I think it will be best if I show you.

Here are a series of three photos that I took with my Canon SD700 IS using the bracketing on timer mode feature in the CHDK. The first is a normal photo that is taken with the default settings of the camera. The second is -4 EV from the first and the third is +4 EV from the first. You can see even in these small thumbnails that all three photos have areas with a lot of detail and areas with almost no detail. Shots like this make for the most impressive HDR results.

After taking the photos I import them into an application called Photomatix Pro (for both Mac and PC) which processes the images into one file and then lets me adjust the tonal range to bring out the optimum detail. The results for my garage photo look like this:



You can see how much detail is brought out in the final photo. Instead of having the boxes in shadow or the outside blown out in brightness the HDR technique finds the detail in different exposures and maps them into one single image.

On Monday I showed some of these photos that I'd out together to Melissa and she immediately agreed to join me in an HDR photo shoot at Hester Park in Seabrook. You can see the results by clicking on the thumbnails below.

Some of the shots turned out better than others, but that's OK. I'm not looking to make art prints from my photos; instead I just seek satisfaction from trying new things. How boring the world would be if people never tried something new.

Houston Weekend Activities

Houston is the fourth largest city in the United States with a little over 2.1 million people calling the city home. If you don't know two million people, it is a pretty staggering number. If Houston were not just a city but instead a state then it would be the thirty-sixth most populace in the United States, between Nevada and New Mexico. If Houston were a its own country then it would be the 141st largest country in the world. If you included all 5.6 million people in the greater Houston area then our city has about the same population as Nicaragua.

With 5.6 million people you are going to find a lot of different walks of life; not just oil men and cowboys thanks very much. Houston has a vibrant and diverse population with a thriving and diverse museum community (including local oddities like the National Museum of Funeral History) and a theater community that is second only the New York City in terms of artistic scope and number of seats. People outside our city may think that we're all George W. Bush loving Christian conservatives, but once you experience the many unique attractions of the city, you'll see how misinformed that opinion is.

Take for example the weekend that Melissa and I enjoyed just these past few days. It was a weekend of cultural oddities ranging from a lowbrow dinner on the side of Galveston Bay to the relatively highbrow attendance of the Houston Ballet's performance of Madam Butterfly and what happened in the middle is certainly unique to Houston. What happened? Well, let's start with Friday night...

On Friday afternoon I left work and high-tailed it to Galveston Island to meet Melissa for her office happy hour. The drive to Galveston late on a Friday was nice and quick and I didn't encounter any traffic to speak of. I've been listening to the biography of Ian Fleming in the car for the past week and the tale of this fascinating man, who was born one hundred years ago this month, kept my attention. I made it to Melissa's office a little after her quitting time and waited around for a bit, but we were still in good time for the happy hour.

I wish I could say that happy hour on Galveston was worth the drive, but it was not. Instead of being a lot of fun with karaoke and lots of new people to talk to, the happy hour ended up being a small handful of people standing around in a muggy bar talking about interoffice politics that I had no insight nor opinion on. I honestly tried to strike up conversations with Melissa's co-workers but I quickly got the impression that they were not receptive to outsiders and I ended up playing a game on my iPhone while nursing a beer in the one cool corner of the bar.

You might think that driving away four gallons of precious fuel would put me in a bad mood, but it didn't really. I brushed off the disappointment and talked Melissa into leaving the island and going north towards home for dinner. Thirty minutes later we were pulling up into the parking lot of Clifton by the Sea in Baclif, Texas. We were seated on the wood deck with a grand view of Galveston bay to our left and a small stage featuring an acoustic cover band to our right. Our dinner there was superb. We started with a creamy, thick cup of crab bisque, served hot enough to require a slow eating pace. That was followed by an assortment of fish and crab tacos, the crab being the better tasting of the two, and the potato boats, which were scooped out baked potatoes baked with cheese, chives, bacon bits and sour cream. All of this was washed down with an absurdly heavy pitcher of fresh sangria.

After dinner we retreated to the house and kept things low key for the rest of the night. Low key for Melissa and I can be as simple as a bottle of wine, some music and a trash-talk filled game of Wii Sports, usually golf. The visions of karaoke will have to wait for another night, and besides, Saturday was going to be a big long day so an early retreat to bed was a good idea.

On Saturday we woke up slowly and got ready for the grand day out. Melissa, Chelsea, her boyfriend and his sister and I were off to watch Houston's Art Car Parade as it ambled down Allen Parkway. The Art Car Parade is something of a tradition for my family; usually we meet my mother and father with wines and cheeses to celebrate Mother's Day. This year my parents are still off motor homing across America so instead of meeting my family we met Melissa's sister and her Bulgarian friends. Toward the end of the parade my friend Carl met up with us too.

The Houston Art Car Parade is the longest running celebration of art cars in the United States. Art cars encompass a wide range of styles and tastes. One of my favorites is a Honda Accord that has been completely covered in mirror shards; another is a dragon car that is well over a hundred feet long. Some of the cars are little more than decorated vehicles with colorful paint, other vehicles are hardly recognized as once being cars, but they move. The majority of the cars look they way they do all year round and are houses in Houston's Art Car Museum; the 'decorated cars' (cars that can be returned to their normal appearance after the parade) are in the minority. Healthy amounts of scorn are heaped on any vehicle that is more advertising than art; for example the Ronald McDonald shoe car is usually booed when it passes for not being art.

The parade started in 1988 with forty decorated cars and has grown to what it is now; the best parade in the northern hemisphere. This year there were over two hundred cars and spectators number around a quarter million people. Anyone thinking that the city of Houston is lock step behind Bush would have been surprised to find a number of art cars specifically used as platforms to call for his impeachment (including the Code Pink M-Peach-mobile).

The Art Car parade is first and foremost a people's parade. It is a locally organized event started by volunteers and entry into the parade is open to anyone with a imaginatively festooned vehicle that can make it up and down the short parade route. Prior to the parade you can walk up and down Allen Parkway and talk to the owners of the assorted cars and during the parade the lines between spectator and participant are often blurred.

Our Bulgarian frineds, Iskra and Itzo, were enthralled with the spectacle of the parade. I can't imagine what someone from the former Soviet Block Bulgaria would think about a parade featuring all these decorated cars. I wonder if they thought Houstonian's crazy for celebrating those who forsake resale value in an effort to make the world a more unique place. Knowing Europeans I imagine they would see the parade as I do; that there is hope for our crassly commercial society after all. I think that the parade helped to show them that Houston is a far more complex city than our reputation leads one to believe.

After the parade ended we slowly gathered up our chairs and coolers and walked to our respective cars. The next stop of the day was to go to Star Pizza for the best pizza in Houston. I've been dining at Star Pizzas for almost twenty years and I have never once had a meal there that was less than stellar. Melissa and I have been there a number of times but our Bulgarian friends and Chelsea's boyfriend and his sister had never been, so they were in for a real treat.

We ordered three large pizzas and settled in for the always-worth-it wait by discussing the NBA finals with Itzo and the cultural difference between Bulgaria and Texas with Iskra. I always enjoy hearing the opinions of others about the state and city I've adopted as my own and their impressions of Houston as being the friendliest and most economical city in America was certainly interesting to hear. As Iskra said, in Houston one can always find work and a place to live.

The final event of an already event filled day was to go to the Miller Outdoor Theater for a showing of Madam Butterfly. The Bulgarians and Carl opted out of this part of the day, but the rest of us could think of nothing better than sitting on the lawn at the MOT and listening to the opera. But it wasn't an opera; Melissa had made a mistake. Instead of an opera we were treated to the ballet version of the story. This made no difference to our group. We had cheeses, crackers, olives and some left over sangria to enjoy so we settled in for a great show.

I have to say that I was impressed with the ballet. I am not a big fan of the more traditional arts; preferring the DIY nature of an art car to the somewhat stuffy formality of a ballet, but this was an interesting story and the performances were expressive enough to tell the story. The free aspect of the MOT also helped me to enjoy it. Most of all I enjoyed it because I got to spend the day doing things I enjoy doing with the people I love to be around. The only thing that could have improved the day in any way at all was to have had Colin along. He missed the entire adventure because it was his mother's weekend. Maybe next year the Art Car parade will move away from Mother's Day weekend and I'll be able to take him to the parade again.

By the time we got home on Saturday, around eleven in the evening, everyone was worn out. We said good bye to Chelsea's friends and retired to sleep feeling stuffed with good food and filled with good memories.