With his face pressed against the eyepiece, he scanned the moonlit ocean in a slow circle.
"Way of a Rebel"
Walter M. Miller
40. The two pieces of glass thus mounted in one frame constitute a compound lens having its own focal plane, shown at F in the figure, and similarly the lenses composing the eyepiece have a focal plane between the eyepiece and the objective which must also fall at F, and in the use of a telescope the eyepiece must be pushed out or in until its focal plane coincides with that of the objective.
"A Text-Book of Astronomy"
George C. Comstock
Beware of the popular error that an object held close in front of a telescope can be seen by an observer at the eyepiece.
"A Text-Book of Astronomy"
George C. Comstock