Examples from literature

• Bud wrenched away from the eyepiece. 
• If the surface has periodic or irregular errors, no sharp image can be obtained, no matter how much the eyepiece may be moved in or out. 
• Now if we push the eyepiece toward the mirror the same distance on the opposite side of the true focal plane, precisely the same appearance will be noted in the expanded star disk. 
• Only one adjustment is necessary, and this is provided by means of the screws which fix the inclination of the eyepiece. 
• The light, after passing through the lenses, is brought to a focus at the lower end of the tube, where the image is examined visually with an eyepiece, or photographed upon a sensitive plate.