| opt. |
variable-focus lens; varifocal lens; zoom lens (by means of internal movement of the lens components with respect to each other these lenses can be changed in effective focal length and thus vary the linear magnification); vari-focus lens (by means of internal movement of the lens components with respect to each other these lenses can be changed in effective focal length and thus vary the linear magnification); variable-focal-length objective (lens); zoom objective (the separation changes between the lens components yield a focal plane which is stationary or does not move outside the limits of depth of focus) |
