Lightness, Brightness, Contrast, and Constancy

Cosmetology treatments on human hair: An SEM study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167160 ◽

1996 ◽

Vol 54 ◽

pp. 940-941

Author(s):

D.F. Bowling

Keyword(s):

High School ◽

High Resolution ◽

Human Hair ◽

Optical Microscope ◽

Convincing Evidence ◽

Brightness Contrast ◽

Sem Study

High school cosmetology students study the methods and effects of various human hair treatments, including permanents, straightening, conditioning, coloring and cutting. Although they are provided with textbook examples of overtreatment and numerous hair disorders and diseases, a view of an individual hair at the high resolution offered by an SEM provides convincing evidence of the hair‘s altered structure. Magnifications up to 2000X provide dramatic differences in perspective. A good quality classroom optical microscope can be very informative at lower resolutions.Students in a cosmetology class are initially split into two groups. One group is taught basic controls on the SEM (focus, magnification, brightness, contrast, specimen X, Y, and Z axis movements). A healthy, untreated piece of hair is initially examined on the SEM The second group cements a piece of their own hair on a stub. The samples are dryed quickly using heat or vacuum while the groups trade places and activities.

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EFFECTS OF AGE AND BRIGHTNESS CONTRAST ON PERCEPTION OF THE WUNDT-HERING ILLUSION

Perceptual and Motor Skills ◽

10.2466/pms.71.6.427-431 ◽

1990 ◽

Vol 71 (6) ◽

pp. 427 ◽

Cited By ~ 2

Author(s):

EILEEN ASTOR-STETSON

Keyword(s):

Brightness Contrast

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Illusory Reversal of Brightness Contrast

Perceptual and Motor Skills ◽

10.2466/pms.1968.27.3f.1169 ◽

1968 ◽

Vol 27 (3_suppl) ◽

pp. 1169-1170 ◽

Cited By ~ 2

Author(s):

Whitman Richards

Keyword(s):

Visual System ◽

Visual Angle ◽

Low Frequency ◽

Brightness Contrast ◽

Linear Behavior ◽

Non Linear

An illusion analogous to Cornsweet's is used to demonstrate how the non-linear behavior of the visual system can be used to obscure low-frequency gradients. The result is a reversal of brightness—from light to dark—as the visual angle of the display is changed.

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