Aperture: Shallow Depth of Field

Aperture refers to the opening in the lens through which light passes before it reaches the film. The aperture can be large or small, or somewhere in between. Remember the experiment we did with the door and the window... an aperture is no different. The aperture is described by an "f/" number, such as f/4, f/11, and so forth. The "f" refers to the focal length of the lens, which we'll discuss later. All you really need to know is that the "f" stands for a number, which is divided the the number below. Thus f/4 is a larger opening than f/8 (think of a pizza, would you rather be offered 1/4 or 1/8 of a pizza? Which is larger?). The largest aperture you're likely to see is f/1.8, the small is f/32. Each drop of one number in the aperture (i.e. f/4 to f/5.6) reduces the light by half... each increase of one number in the aperture (f/16 to f/11) doubles the amount of light coming in.

When the aperture is open (such as f/2, f/4), the amount of picture that is sharp is shallow, thus the term "shallow depth of field". The giraffe picture gives you an example... the subject is sharp, but the background is blurred. Your assignment, due Oct. 3, is to turn in a print (with contact sheet and data sheet) demonstrating shallow depth of field. On this blog you should add comments about subjects you think would be suitable for shallow depth of field, along with questions. Good luck!

Shutter Speed, week of Sept. 15

Now we're going to try some blurred motion. To create the effect of blurred motion, part of the picture must be sharp and clear (the part that's not moving) and part must be blurred. Look at the two pictures from last week below and see how, while the water in one is blurred, the lock around is sharp (well, relatively). I've posted examples here from Grand Central Station and Times Square.

Please add your comment about HOW you'll create blurred motion (hint: think shutter speed) and WHAT your subject will be.

Shutter Speed, week of Sept. 11

The speed of the shutter door opening and closing controls MOTION. Motion can either be frozen or blurred. Use the comment section to discuss with each other how you would freeze motion, and what type of subjects would be suitable for freezing. If you left your comments under the previous post you'll still get credit. Your assignment, due Friday, is to shoot and develop a roll of frozen motion.

Above are pictures taken with fast and slow shutter speeds from our hike last week.