The characteristic productions of the third among the modern schools are monochromatic and translucid enamels.
Thus a monochromatic image of the sun is built up on the fixed photographic plate.
SPECTROHELIOGRAPH, an instrument for photographing the sun with monochromatic light.
White light), which is dispersed by refraction, and monochromatic (Gr.
There are " chromatic differences " of the distances of intersection, of magnifications, and of monochromatic aberrations.
In monochromatic light, then, the interference pattern is characterized by three systems of curves: the curves of constant retardation p = const.; the lines of like polarization = const.; the curves of constant intensity I = const.
It is an easily traced outgrowth of the second branch of the Cloisonless first school just described, for one can readily underEameis stand that from placing the decorative design in a monochromatic field of low tone, which is essentially a pictorial method, development would proceed in the direction of concealing the mechanics of the art rn, order to enhance the pictorial effect.
At that time monochromatic photographs of the sun were first made on Mount Wilson with the red (Ha) line of hydrogen, previous hydrogen photographs having been taken with H/3, Hy or HS in the blue or violet.
Thus a monochromatic image of the sun, formed of a great number of successive images of the spectral line employed, will be built up on the plate.
These glazes were not monochromatic: they showed differences of tint, and sometimes marked varieties of color; as when chocolate-brown passed into amber, or black was relieved by streaks and clouds of grey and dead-leaf red.
Seifu YOhei, however, has the special faculty of manufacturing monochromatic and jewelled porcelain and faience, which differ essentially from the traditional Kioto types, their models being taken directly from China.
The porcelains of Owari and Arita naturally received most attention at the hands of the Hyochi-en decorators, but there was scarcely one of the principal wares of Japan upon which they did not try their skill, and if a piece of monochromatic Minton or Svres came in their way, they undertook to improve it by the addition of designs copied from old masters or suggested by modern taste.
In the products of the KiOto branch the decoration generally covered the whole surface of the piece; in the products of the other branch the artist aimed rather at pictorial effect, placing the design in a monochromatic field of low tone.
According to Krummel the following relations hold, good at 18° C. for the monochromatic light of the D line of the sodium spectrum in units of the fifth decimal place.
In the case of narrower lines, however, higher dispersion is required to prevent the light of the continuous spectrum on either side of the dark line from blotting out the monochromatic image.
(a) Monochromatic Aberration.
On the other hand a stream of strictly monochromatic light with a polarization-vector that is entirely transversal must be (in general elliptically) polarized.
Consequently it follows that common light cannot be absolutely monochromatic. The conditions that are necessary in order that a stream of light may behave as natural light have been investigated by Sir G.
281), and it may be shown that two polarized streams of a definite character are analytically equivalent to common light provided that they are of equal intensity and oppositely polarized and that there is no common phase relation between the corresponding monochromatic constituents.
' - sine 2p When the primitive light is white, this expression must be summed for the different monochromatic constituents.
With a combination of plates in plane-polarized and plane-analysed light the interference pattern with monochromatic light is generally very complicated, the dark curves when polarizer and analyser are crossed being replaced by isolated dark spots or segments of lines.
Arago pointed out, by supposing that in passing through the plate the plane of polarization of each monochromatic constituent is rotated by an amount dependent upon the frequency - an explanation that may be at once verified either by using monochromatic light or by analysing the light with a spectroscope, the spectrum in the latter case being traversed by one or more dark bands, according to the thickness of the plate, that pass along the spectrum from end to end as the analyser is rotated.
Consequently the monochromatic class includes the aberrations at reflecting surfaces of any coloured light, and at refracting surfaces of monochromatic or light of single wave length.
If, in the first place, monochromatic aberrations be neglected - in other words, the Gaussian theory be accepted - then every reproduction is determined by the positions of the focal planes, and the magnitude of the focal lengths, or if the focal lengths, as ordinarily happens, be equal, by three constants of reproduction.
For infinitely distant objects the radius of the chromatic disk of confusion is proportional to the linear aperture, and independent of the focal length (vide supra," Monochromatic Aberration of the Axis Point "); and since this disk becomes the less harmful with an increasing image of a given object, or with increasing focal length, it follows that the deterioration of the image is proportional to the ratio of the aperture to the focal length, i.e.
Two other conditions may also be postulated: one is always the elimination of the aberration on the axis; the second either the " Herschel " or " Fraunhofer condition," the latter being the best (vide supra, " Monochromatic Aberration ").
The Gaussian theory is only an approximation; monochromatic or spherical aberrations still occur, which will be different for different colours; and should they be compensated for one colour, the image of another colour would prove disturbing.
Substances separated from one another by a spherical surface, then there are two points on the axis where they can be reproduced free from error by monochromatic light, and these are called " aplanatic points."
As the source of monochromatic light a bright sodium burner is used, and the rotation, which is exactly proportional to H, is measured by an accurate polarimeter.