High Definition Algonquin

Tay & I are back from our first (together) camping adventure! For most of last week we were on a whirlwind, poorly planned and much needed vacation from the city in Algonquin Provincial Park, about 3 hours north of Toronto. This was a great opportunity for me to try out the HDR capabilities of my 7-year-old Pentax Optio 330GS digital camera (3.2 megapixels!) with the new tripod I picked up at Factory Direct for about five bucks.

For those not familiar with high-dynamic-range (HDR) photography, have a look at this Wikipedia article. Basically, HDR overcomes the optical limitations of conventional imaging by taking several (three or more) images of a scene at different exposure levels, combining the images with software, and ending up with a compiled image more closely resembling what is seen by the human eye. The article has an interesting discussion on the methods that can be used to achieve this and the science behind how the eye sees an image, so I won't try to explain it here.

For me, and for most, this means I can record both the bright and dark areas of a scene reliably. My end result conveys the details of the scene, within the limited dynamic range of the media (your monitor) with a tradeoff in contrast. Following are some examples from our Algonquin trip.

This is a picture of an abandoned bridge constructed by the 19th-century logging town of Mowat, at the north end of Canoe Lake. The camera is incapable of recording different exposures for different parts of this image, so it automatically calculates the proper exposure to record the center of the frame (the bridge and trees) and takes an image, which results in the sky and most of the reflection in the water being overexposed. By taking two more images, one with a darker exposure to record the sky, and one with a brighter exposure to reveal the details in the dark reflections, the entire scene can be recreated.

In the resulting image, the details of the sky, the trees and the bridge are all clearly visible. This image represents the scene in a way that is much closer to what I actually saw from the canoe at that time, by combining the darker sky with the lighter forest.

One issue that can happen, which I just noticed is apparent in the bridge in this HDR photo, is that small variations between the frames result in ghosting in the final image. In this photo, since the canoe was moving slowly through the water and my 7-year-old camera can only take 1 picture about every 2 seconds, each of the three frames is taken from a slightly different angle, and the bridge is not in exactly the same spot in each one. Take a look at the photo full-size and you'll see what I mean.

From the bridge we canoed north along Potter's Creek, a peaceful trip but mostly not good for photography. We stopped here at a portage for lunch and to get out of the canoe for a bit. For the same reason as the bridge picture above, this scene would be difficult to render with a single photo because of the different exposures between the sky, the forest and the creek. This HDR rendering captures all three. Plus I think it looks pretty. Since the wind was mostly calm and the camera was on a tripod, I've avoided the ghosting effect apparent in the bridge picture. The clouds were moving pretty fast but only one of the images really catches the detail in that part of the frame. I plan to blow this up to 5x7 or so and get it printed, although I don't know exactly where it will fit in our apartment yet.

Although I have many more photos from the trip, I'm having issues trying to arrange them on the blog. At some point I guess I should open a Flickr account (so I'm told) and maybe this will be the motivation to do it. Anyway that's it for now. Get out there and take more photos!