Successive Color Contrast Effect
Posted on 07/30/2012
The successive contrast effect is the result of two colors being viewed in succession. The first color can affect the perception of the second color because the first color remains in the viewer’s perception and is known as an "afterimage". For example, if a doctor takes a shade from the maxillary right and immediately takes another shade from the maxillary left, it is likely that the shade on the maxillary right will affect his/her perception of the shade on the maxillary left.
Afterimages are divided into two categories: positive afterimages and negative afterimages. Positive afterimages are afterimages that retain the color of the original image. For example, if the viewer sees a red image, the afterimage will be red. A negative afterimage is when the afterimage is an opposite or complementary color to the originally viewed color. For example, if the original color was red, the viewer will retain a green color as the afterimage. The causes of positive afterimages are not well known, but the causes of negative afterimages are attributed to long visual contact and overstimulation of the rods resulting in a loss of sensitivity.
The easiest and probably most effective way of dealing with the afterimages is to view a neutral color, such as gray, between each shade selection. Viewing the neutral color will help to reduce or eliminate the effects of the original color on the perception of the new color.
Portions of this post were adapted from the book:
Fundaments of Color - Shade Matching and Communication in Esthetic Dentistry published by Quintessence Publishing Co. Inc and written by Dr. Stephen J. Chu, Dr. Alessandro Devigus, Dr. Rade D. Paravina and Mr. Adam J. Mieleszko. and the
Wikipedia article/s:
http://en.wikipedia.org/wiki/Contrast_effect
http://en.wikipedia.org/wiki/Afterimage
Afterimages are divided into two categories: positive afterimages and negative afterimages. Positive afterimages are afterimages that retain the color of the original image. For example, if the viewer sees a red image, the afterimage will be red. A negative afterimage is when the afterimage is an opposite or complementary color to the originally viewed color. For example, if the original color was red, the viewer will retain a green color as the afterimage. The causes of positive afterimages are not well known, but the causes of negative afterimages are attributed to long visual contact and overstimulation of the rods resulting in a loss of sensitivity.
The easiest and probably most effective way of dealing with the afterimages is to view a neutral color, such as gray, between each shade selection. Viewing the neutral color will help to reduce or eliminate the effects of the original color on the perception of the new color.
Portions of this post were adapted from the book:
Fundaments of Color - Shade Matching and Communication in Esthetic Dentistry published by Quintessence Publishing Co. Inc and written by Dr. Stephen J. Chu, Dr. Alessandro Devigus, Dr. Rade D. Paravina and Mr. Adam J. Mieleszko. and the
Wikipedia article/s:
http://en.wikipedia.org/wiki/Contrast_effect
http://en.wikipedia.org/wiki/Afterimage
