Saturday, April 18, 2009

Virginia Bluebells


It’s easy to miss the chance for a good image if you don’t keep track of the calendar, especially in the spring. At this time of the year, the landscape photographer is overloaded with opportunities as the season of renewal races with frenetic speed. But the opportunities are usually brief and so it helps to maintain a “schedule” of what is going to happen, when, and where. For example, every year in mid-April, a nondescript wooded area in northern Virginia is briefly transformed into a dazzling carpet of blue and white. Bordering a stream known as Cub Run, this 75-acre tract in Bull Run Regional Park seems to have the perfect conditions for the Virginia bluebell.

The plant has a fleeting existence above ground, appearing for just a brief period each year. There are only a few weeks of warm weather before the life giving sunlight is blocked out by the emerging leaves of the overhead tree canopy. The bluebell must grow rapidly and it quickly reaches a height of about two feet. Then clusters of bell-shaped blossoms emerge just as the first insect pollinators, critical to the plant’s survival, begin to search for nectar.

The Bluebell can be found in many places in the Northern Virginia area, but one of the best locations is at Bull Run Regional Park, near Centreville. Other locations include the nearby Stone Bridge across Bull Run on the eastern edge of Manassas battlefield, Great Falls National Park, and the adjacent River Bend Regional Park.
Read more!

Friday, April 10, 2009

Photography: Painting with Light


The word, “photography” derives from the Greek language as “writing with light.” But I find it easier to think of it as painting with light. A photographer’s subject must be illuminated, and the color of the subject is determined by the color of the light striking it. There are many ways to change that color (choice of film, adjusting the white balance, etc.) but the starting point is the light source one is using and for the landscape photographer, that usually means the sun. So knowing what happens with sunlight at different times of the day as well as different times of the year helps me anticipate photographic opportunities before they happen.

The subject here is the Francis Scott Key Bridge, from a vantage point on the Washington, D.C. side of the Potomac River. Figure 1, on the left, was taken about 30 minutes before Figure 2. The latter, shot a few minutes before sunset on September 21, 2004 using Ektachrome VS 100 slide film. Anyone who lives in the Washington area knows that the Key Bridge is not painted gold. The normal color of the bridge is shown in Figure 1, but the color shown in the second image is as I saw it and not the result of a Photoshop technique. The magic lasted only a few minutes and probably was witnessed by only a few people, mostly boaters and the staff of the boathouse from whose dock the picture was taken.

All landscape photographers are aware that sunlight is composed of many colors (or wavelengths as the scientific folks would say). These colors are shown in a rainbow or when the light passes through a prism. We also are familiar with the yellow or red light that is often associated with a sunrise or sunset. The warm golden tone is caused is the fact that the sun is close to the edge of the earth’s horizon and the light must pass through a greater amount of the earth’s atmosphere. The air scatters the shorter wavelengths (violet and blue) while the longer wavelengths (yellow, orange, and red) pass through.


Knowing that a sunset can produce this effect, however, is not enough to capture an image like the one in this example. It is also necessary to know where the sun will set. In this case, the bridge runs almost due north-south (a bearing of 18 degrees east of north when crossing from Virginia), meaning that the upriver side faces almost due west. And September 21, 2004 was one day before the fall equinox when the sun sets precisely at due west. Therefore, I knew that for a few days around that date I had a good chance of capturing a image of the bridge being illuminated by a golden sunset.

Read more!

Monday, April 6, 2009

Action Panorama Images



Sometimes it takes time for an idea to be implemented. I happen to live just 5 minutes from Great Falls National Park, and last summer I went over to photograph the annual whitewater festival that features kayakers navigating the falls. I'd been experimenting with Photoshop's "Photomerge" capability and thought this would be a good opportunity to try something a little different: a sports action image.

For those who are not familiar with Photomerge, the software basically stitches together several photographs to make a single image, hopefully so seamless that the viewer cannot discern the effect. Most often, the subject is static with the photographer using a tripod to carefully pan the camera in a precise arc from one side to the other in order to capture segments of the overall image. Then, back at the computer, the separate images can be aligned and blended by Photoshop's photomerge function.

In this case, however, there was considerable action and movement, especially the large volume of water coming over the falls and the competitors navigating the falls one at a time. In addition, there were several people moving around the scene. Safety personnel were standing on the rocks and one or two kayakers were maneuvering around the base of the falls to assist anyone who made a mistake. And most importantly, competitors were coming over the falls one at a time.

My camera was a Nikon D-200 using a Nikon 80-400 mm VR zoom set at 340 mm. Most often, a panorama is shot with the camera oriented in the horizontal, or landscape, format. But this time I concluded that a vertical, or portrait, format would enable me to zoom in closer to the scene. The downside was that this would require 6 exposures across the face of the falls instead of 3 to get the full width of the scene. I also decided to try to shoot the image without a tripod, because I needed to react quickly to the action. My settings were ISO 400, 1/1000th of a second at f/8.0, shooting RAW.

I photographed each kayaker as he or she came over the falls. If I felt that I had captured a good image, I then quickly swung the camera to the left and took a series of overlapping images moving to the right across the face of the falls before the next competitor arrived. Because of the changing light conditions and the passage of time (the event lasted about 2 hours), it was necessary to capture the whole scene at essentially the same time.

For a variety of reasons, I did little with the results until recently. But finally, I opened up the RAW images and selected the set that seemed to have the most promise. As I launched Photoshop, I wondered whether the photomerge function would be able to handle that thundering water and the fact that some of the people appeared in more than one image. Putting together a set of images of buildings with straight lines or even a landscape in which nothing is moving is one thing. But this could turn out to be a joke.

The initial steps are always: File > automate > photomerge. I brought in the six images and selected the default layout option, "Auto." Although it took some time, I was stunned to see that the results were flawless. The water had been perfectly blended together and the software had chosen one image of each person in the scene. I flattened the layers (photomerge creates a separate layer for each image that is used), cropped the scene as needed, and then adjusted contrast, brightness, and sharpness. It looked great on the monitor.

But how would it look as a print? Even though I have an Epson 7600 printer in my studio (which can in theory print something 24" wide and as long as the amount of paper left on the 100-foot roll), I decided to be cautious and started with an 8' X 20" version. This, in effect, was the same as enlarging a single 10 megapixel image to an 8" X 10" print, which is definitely not a stretch.

The result was as sharp as a tack. I realized that it could easily be doubled in size without any obvious degradation, giving me a 20" X 42" panorama, almost 4 feet wide. But committing to that amount of ink and paper makes one nervous. Will the printer perform without any hiccups? As it turned out, it took about 50 minutes for the job to run and I was nervous as a cat until the cutter blades completed the task and I placed the print on the viewing table. Everything was fine, even though it was nine months between the time the image was taken and the print was finally produced.
Read more!