A Short Course in Digital Photography/Light and Lens: Chapter 3 - Collective Notes

Looking at Light and Exposure

Quality of an image
Pixels: store information from photos
 - More pixels = finer picture
Resolution: measures the fineness of an image in ppi (pixels per inch)
 - As size goes up, resolution goes down

Color
Color is made by mixing 3 primaries (red, blue, yellow) -- can be additive or subtractive
   - all printers use subtractive primaries

Characteristics of color:

Hue: the 'color' of the object
Saturation: Measure of 'purity'
Value: Measure of brightness/darkness

All color captured by photographs are impressions of the real color (cannot be duplicated exactly as we see them)

Characteristics of a color photograph: white balance, color saturation, contrast
Light source changes how light is reflected, cameras can correct/adjust for this in terms of tint/temperature

Exposure: Determines quality of light and color
Exposure = intensity x time
   - measured in 'stops'

Color Histograms v. Light Meters
Light meters measure middle gray, doesn't account for colored tones in most cases
Color histograms: measure color quality in relation to light
Expose to the right: any empty space should be to the left (easier to darken than to lighten)
   - push as far to the right as possible without highlight/light 'clipping'
   - brackets are helpful if unsure (take multiple exposures)

You can meter for different parts of the scene and combine exposures (allowing for perfectly exposed photos in high contrast or backlit scenes)