Lecture Notes: Principles of Exposure - Capturing Action and Controlling Motion Blur

Lecture Notes: Principles of Exposure

Exposure Triangle

Aperture: Mechanical feature: a series of blades that are closing and opening over each other;

Controls how much light is being let through your camera lens; decreases or increases the diameter of the lens.

Smaller aperture = crisper image, lets in less light, light travels through only the middle of the convex lens (which is less bent than the edges and so the refracted/bent less). A narrow/smaller aperture setting has a higher number, like 8 or 16.

Larger aperture, "fast lens", lets a lot of light in quickly = narrow depth of field (small amount of picture in focus), softer focus. A larger aperture has a smaller number like f/ 1.4

Higher quality lenses have more blades.
F/stop is sometimes synonymous with aperture, but is also used more generally to talk about how much light is in a shot (which all 3 elements of the exposure triangle.
Rule of exposure: "Each Change In ISO Is Equal To One Full F-Stop"
1 stop is changing the light settings by a factor of two.

Shutter speed:

Mechanical feature. How fast the shutter opens and closes;
the longer the shutter speed is open the more motion blur is captured in the shot.
The mirror reflects the light through the viewfinder. When the camera is clicked, the mirror is flipped out of the way to expose the film to the light of what the camera is pointed at.
Fast shutter speed example 1/4000 of a second. Slow shutter speeds examples: 1/10th of a second, or 1 second.

ISO:
Sensitivity of the camera sensor (great for dark conditions), but however, the more sensitivity there is more "noise" or grain. We want to avoid changing this when possible.

White balance: match the whites with the lighting in the environment you're shooting in.

Every time you change one element of the exposure triangle, the other elements are affected.
E.g.
if ISO is increased, more light is let in, so if you want to keep the same exposure, aperture would need to be decreased to limit the light, and shutter speed could be sped up to decrease the light let in - so that an overall balance is created.