Abstract: An autocollimating alignment telescope automatically turns a lamp on in the autocollimating operational mode, and automatically turns the lamp off in the alignment telescope operational mode. The telescope has reticles which are replaceable in the field, as well as eyepiece and lamp housings whose mountings are interchangeable. The telescope also has an assembly for preventing jamming of the traveling lens assembly of the telescope, as well as independently operable coarse and fine adjustments for the traveling lens assembly.