Spherical-aberration Sentence Examples

James Gregory, in his Optica Promota (1663), discusses the forms of images and objects produced by lenses and mirrors, and shows that when the surfaces of the lenses or mirrors are portions of spheres the images are curves concave towards the objective, but if the curves of the surfaces are conic sections the spherical aberration is corrected.

He did not attempt the formation of a parabolic figure on account of the probable mechanical difficulties, and he had besides satisfied himself that the chromatic and not the spherical aberration formed the chief faults of previous telescopes.

It requires the middle of the aperture stop to be reproduced in the centres of the entrance and exit pupils without spherical aberration.

Of thin positive lenses with n= 1-5, four are necessary to correct spherical aberration of the third order.

In a plane containing the image point of one colour, another colour produces a disk of confusion; this is similar to the confusion caused by two " zones " in spherical aberration.

The spherical aberration of a diamond lens can be brought down to one-ninth of a glass lens of equal focus.

Correction of the spherical aberration in strong systems with very large aperture can not be brought about by means of a single combination of two lenses, but several partial systems are necessary.

If, by these methods, a point in the optic axis has been freed from aberration, it does not follow that a point situated only a very small distance from the optic axis can also be represented without spherical aberration.

The removal of the spherical aberration and the sine-condition can be accomplished only for two conjugate points.

A second method of correcting the spherical aberration depends FIG.

By using these glasses and employing minerals with special optical properties, it is possible to correct objectives so that three colours can be combined, leaving only a quite slight tertiary spectrum, and removing the spherical aberration for two colours.

A second method for diminishing the spherical aberration was to alter the distances of the single systems, a method still used.

In the apochromats the chromatic difference of the spherical aberrations is eliminated, for the spherical aberration is completely avoided for three colours.

The spherical aberration correction is in this region too.

I realize that this extends the tube length and will cause some spherical aberration.

It incorporates aspherical lens elements in the front, as well as rear lens groups, to correct spherical aberration.

Another obvious inference from the necessary imperfection of optical images is the uselessness of attempting anything like an absolute destruction of spherical aberration.

A system fulfilling this condition and free from spherical aberration is called " aplanatic " (Greek a-, privative, irXavrl, a wandering).