Melles Griot has added a full line of apertures, spatial filters and microscope components to its online catalog. Visitors to its Web site will find specifications on reticles, resolution test targets and focusing microscope bodies, which accept standard eyepieces, objectives and accessories and which are available with coarse focusing or with both coarse- and fine-focusing mechanisms. Pinholes and slits are available mounted, unmounted or in sets for applications that include image analysis and spectrometry. Pin-actuated iris diaphragms provide a continuously variable field stop for controlling the f number of an optical system or for adjusting beam diameter.