In our class this week, we continued our discussion about exposure, that is, f-stops, or apertures, and shutter speeds, These are the elements along with your film speed that are at play in properly recording light through your camera to create an image.
Other topics we touched on were camera shake which is a common result for blurry pictures resulting from a shutter speed too slow to hand hold a camera. The ways to solve the problem are through decreasing the amount of movement by using a higher shutter speed or a tripod. Panning is an purposeful blurring effect that you can get through setting your camera at a slow shutter speed and following a moving subject. You can also create an effect with a slow shutter speed and a tripod when subjects such as traffic or a ferris wheel are moving and your camera is steady.
Along with f-stops, we talked about depth of field which mean "the amount in focus." Depth of field is increased and decreased with the size of your aperture (f-stop). It can be used to your benefit as we saw in some of our class photos from Monika and Marco who had their subject in focus with the distracting background blurred. An aperture of f2.8 would have only a small portion of a scene in focus, while an aperture of f16 would have nearly the entire scene in focus (link). This was the idea behind Ansel Adams's storied Club F64 which loved the high f-stop that would get them photographs with tremendous sharpness.
We looked at different lenses and the effect each of them makes. Wide angle lenses such as a 24 mm, will allow you to record more of a scene and let you photograph a slower shutter speeds. A normal lense such as a 35 mm or 50 mm see without much distortion and are close to what humans see. A telephoto lense such as a 200 mm will bring a subject closer to you and compresses the scene. A macro lense will allow you to focus on and photograph subjects very closely.
One point that I made which I will continue to make is physically moving around to look and explore. While you can use large aperture such as f4 to blur out a background, you can simply move to find a less distracting or "cleaner" background.
Photographers we looked at this week were Dorothea Lange (Migrant Mother), Steve McCurry (Afghan Girl), Joe Rosenthal, Mary Ellen Mark, and portions of project from Eugene Richards.
Links:
Exposure Wheel (graphic)
F-stops/Apertures (graphic)
Shutter Speeds (animated illustration)