definition
The lens (or combination of lenses) at the eye end of a microscope or telescope by which the image is viewed.
These eyepieces are very convenient in use, for when they are changed the lower focus always falls in about the same plane.
This gave an orthoscopic image even in ordinary eyepieces.
In both cases two eyepieces are employed, one to view each separate web.
There are three eyepieces which are mounted on a revolving sleeve in such a way that any one of them can be quickly brought into use, to give the magnification suitable to the height of the mast.
These eyepieces are intentionally provided with a different chromatic magnification, which however is in opposition to that originating in the objective.
As powerful achromatic objectives show differences of chromatic magnification in the same way as apochromats, compensation eyepieces can be used in combination with these objectives.
The system of Porro prisms employed affords a convenient method of adapting the ends of the eyepieces to the interpupillary distance.
Some appear to be capable of being used with the high power objectives which normally perform better with compensating eyepieces.
Best results are obtained with high point wide field eyepieces.
The unit contains a reducing lens which restore the field of view to cover approximately the same area as standard x10 widefield eyepieces.
Small German periscopes were usually 1 metre or 2 a metre in length and had two eyepieces giving magnifications 10 and 15 diameters.
In both eyepieces micrometers or cross-wires are used for measuring in the plane of the real FIG.
A second manner of making stereoscopic observations employs stereoscopic eyepieces.