In order to characterize the materials employed in the achromatic
doublet, the corresponding behavior of the refractive index versus wavelength of incident light is shown in Figure 1.
Figure 7 shows the relationship between observational average ratings and visibility level for achromatic
and colored targets, which were lit by LEDs.
The usage depends on various factors, such as technical properties of the reproduction process, reproduction of tones and colors mostly in highlights and midtones, and as possible dedicated demands in achromatic
(black and white) reproduction.
On the brightness (achromatic
) plane composed of a brightness axis, Z3, and darkness axis, Z4, saturated colors are located near the center, while less saturated colors area close to the periphery (Figures 3 B, C).
Two different strategies for generation of black separation were used, with various combinations of achromatic
For example, research directly related to the Word Colour Survey (Kay et al., 1997) uses an array of 330 colour patches from the Munsell Atlas colour surface (maximum possible saturation for each hue and lightness) plus ten pure achromatic
stimuli (a grey scale).
Ninety-eight college students were asked to indicate their emotional responses to five principle hues (i.e., red, yellow, green, blue, purple), five intermediate hues (i.e., yellow-red, green-yellow, blue-green, purple-blue, and red-purple), and three achromatic
colors (white, gray, and black) and the reasons for their choices.
However it was not until the 19th century when the use of achromatic
lenses were implemented to reduce distortion that the telescope came into its own right, and became a popular scientific instrument.
The discussion is focused on issues of color space viewed against a simple achromatic
surround, and does not address color appearance under widely varying light and surround conditions.
The magnifiers incorporate achromatic
, coated multiple lens systems that provide bright, crisp, clear, color-corrected, and distortion-free viewing.
Ostergaard and Davidoff (1985) found that colored photographs presented tachistoscopically were named more quickly than achromatic
photos, but that chromaticity had no effect in a recognition task employing the same stimuli.
Here is a multicoated, 3.1-inch (80-mm) achromatic
refractor of 900-mm focal length (f/11) with a German equatorial mount, dual-axis slow-motion controls, and an adjustable aluminum tripod.