The Early Bird Gets the Worm (and a Few Photo Tips)
Blog entry: February 4, 2012
I normally take photographs in the afternoon, when all the worms have long since returned to the soil. But an early morning visit to Whitman Mission last week found this little guy traveling down the path around the mission grounds at an alarming rate (by worm standards that is!).
I shot this photograph with my camera's aperture set to f/5.6. The aperture of a camera lens controls how much light enters the camera by opening and closing a diaphragm within the lens. A low f-number (also known as f-stop), such as f/3.5 or f/5.6, means that more light is able to enter the camera. One consequence of a lower f-stop is that only objects at a certain distance from your lens will be in focus. Objects farther or closer than this distance will be thrown out of focus, as in this shot where the worm is sharp but the background and foreground are blurry. This concept is known as "depth of field". A large (or "deep") depth of field simply means that both the nearest and farthest objects in your field of view will be sharply in focus. This can be achieved by increasing the f-stop on your camera and letting in less light (most cameras will go up to at least f/8 or f/11, while many professional lenses can reach f/35 or greater). Conversely, a small (or "shallow") depth of field is what we find in this photo, where only objects at the same distance as the worm will be in focus. This can be a good photo-taking strategy if you want to highlight one particular object, such as the worm. The lower your f-stop, the shallower your field of view will be.
Feeling a little disoriented? That might be because this picture is actually upside down! A calm, windless, winter afternoon left the millpond completely still which allowed me to capture this image of a tree and the sky perfectly reflected off the water's surface. I was also attracted by the handful of bright red leaves submerged at the edge of the pond. I used a polarizing filter and held the camera at an angle in order to eliminate the reflection from the water at the edge of the pond. This is what allows us to see the leaves beneath the water and why the sky appears to gradually turn grey and then black. I then rotated the photo 180˚ in Photoshop to produce the image you see here. For more about polarizing filters, take a look at some of our previous blog entries: http://www.nps.gov/whmi/photosmultimedia/goodclouds.htm and http://www.nps.gov/whmi/photosmultimedia/of-panoramas.htm
Did You Know?
Wagons used on the Oregon Trail had to carry nearly 2000 pounds of supplies. They traveled 2000 miles or more to the Oregon Country. Most wagons were pulled by oxen as they could eat the prairie grass and survive without lots of food for lengthy periods.