North Texas PC User’s Group Photoshop SIG Hillary Morgan Ferrer Session 3 - August 18, 2007

What we will cover today Color Theory Histograms Exposure Correcting for Exposure Correcting for Color

COLORCOLOR

Color Theory The Color Wheel Really Young Girls Can Become Mothers Boys make really young girls cry To take out x you add y

Color Opposites To take out Red, add Cyan To take out Green, add Magenta To take out Blue, add Yellow And Vice Versa (examples in PS)

Ways to Manipulate Color in Photoshop Levels Curves Hue/saturation Selective Color Color Balance Photo Filters Channel Mixer

How Photoshop sees Color Photoshop sees color in terms of numbers These numbers are graphed onto a graph called a “histogram” 8 bits = 256 shades = black 255 = white

Histograms For each color, you have this histogram telling you how much of which shade of each color the picture contains. The colors exist in something called “Channels” RBG, CMYK

Normal Histogram No excess of bright whites No excess of Dark Darks

Bright White Histogram Picture is predominantly white, so we see a predominant number of pixels on the right side of the histogram

Dark Histogram Picture predominantly black, so we see a predominant number of pixels on the dark end

Correcting Exposure Levels –Slide on RGB scale –Slide on R,G,B scale –Black point, white point droppers –Finding Black/White points with alt –Shifting midtones

Correcting Exposure Curves –Overall darken/lighten –Contrast curve

Over/Under

Over/Under Corrected

White Balance Makes Colors Neutral Bright Sun, Cloudy, Open Shade, Tungsten, Flash, Strobe, Halogen MUST do before with JPG Can do post with RAW Measured in degrees Kelvin Higher the degrees, the bluer it looks Lower the degrees, the redder it looks

Light Temperatures Open Shade/Cloudy Direct Sunlight Fluorescent Tungsten

Shot on Cloudy Day

Eyedroppers in Levels

Ways to neutralize color in PS Even when color balance in camera, can still get color cast Gray card Eye dropper in curves, levels Auto color By sight (assuming you have calibrated monitor) Example (John roar)

Homework …