Notice: Trying to get property 'num_rows' of non-object in /var/www/kidsnetau/dictionary_content.txt on line 149
Hyponyms: autofocus, biprism, camera lucida, coelostat, collimator, diffraction grating, grating, diffuser, diffusor, finder, viewfinder, view finder, Kerr cell, laser, optical maser, lens, lense, lens system, Nicol prism, planetarium, polarimeter, polariscope, prism, optical prism, projector, Rochon prism, Wollaston prism, stereoscope, viewer