graticule, reticle, reticule

viewfinder, magnification, loupe, lens, aperture, camera lens, pentaprism, refractor, penlight, collimator, image intensifier, laparoscope, iris diaphragm, retroreflector, convex lens, periscope, arcsecond, diopter, infrared, binoculars, focal length, telescope, flashgun, magnifier, endoscope, celestial sphere, zoom lens, nosepiece, ophthalmoscope, collimating, imager, epsilon aurigae, parallax, parabolic mirror, optics, eyehole, coronagraph, fisheye, fluoroscope, oblique angle, gimbal, peripheral vision, monochromator, spectroscope, gimbals, monopod, colonoscope, projector, photomultipliers, camera, enlarger, prisms, photometer, photodetector, bolometer, spyglass, parabolic reflector, diffraction grating, baseplate, interferometer, goniometer, equilateral triangle, pinhole, rhombus, gnomon, fresnel lens, magnifying glass, tripod, fovea, needlenose pliers, stereographic, gravitational interaction, reticle, borescope, photodiodes, convex, refracting telescope, scopes, earthshine, circular polarization, stereoscope, newtonian telescope, microscopes, wavefront, isosceles triangle, otoscope, vignetting, illuminance, glassless, headlamp, sunblind, emissivity, illuminator, toric lens, diffraction, colorimeter, thumbwheel, crystalline lens, photocells, zoom, telephoto lens, reticule, eyepieces, ocular, lenses, microscope, caliper, rheostat, spectrograph, galvanometer, micrometer, boiler, bracket, condenser, nozzle, oscilloscope, track, absorber, achromatic, additive, adherend, adsorbent, allelic, alliterative, alphanumeric, analgesic, antenna, antigen, antisymmetric, antitoxin, apperceptive, astatic, axle, ballast, barycentric, bilinear, bipropellant

compound microscope, filar, graticule, jeweler's loupe, loupe, newtonian reflector, newtonian telescope, peep sight, reflecting telescope, reflector, refracting telescope, reticle, reticule

binocular, field glasses, light microscope, opera glasses, optical telescope, sight

lens system