Optical System    All microscopes come standard with an infinity corrected optical design (F=200)    Viewing Heads    Units are supplied with either a standard Siedentopf type binocular head inclined at 30 degrees or a trinocular Siedentopf head inclined at 45 degrees. Interpupilliary distance is adjustable from 53mm to 75mm.     A graduated diopter adjustment is provided as a standard feature on the left eye-tube of all units.     Eyepieces    Paired SWH10X, widefield, high eye-point eyepieces, FN 22, with a 25mm reticle mount is standard on all units. Optional SWH15X, SWH20X and SWH10X-F focusing eyepieces are available.     Nosepiece    Quintuple, side facing nosepiece, with positive precision click stops.    Objectives    TC Planachromat, TC Planachromat Phase or TC Planachromat fluorescence objectives are provided on respective models.     Plain Stage    A 180mm(X) x 245mm(Y) plain stage with replaceable glass insert with 45mm opening.     Optional Attachable Mechanical Stage    112mm(X) x 72mm(Y) movement with built in test plate holder and drop down ergonomic coaxial controls.     Optional Specimen holder Include     1" x 3" Slide, chamber, 35mm, 55mm, 65mm Petri dish, Terasaki plate, and Hemacytometer holder.     Focus Mechanism    Ergonomically low positioned, coaxial, coarse and fine focus knobs with adjustable tension control. Range of travel: 9mm total, 1.0mm up and 8mm down. Rotation of fine focus: 0.2mm per revolution.     Illumination    All units come equipped with a 6V/30W halogen lamp. An aspheric condenser lens, a diffusion filter and heat absorbing filter are also incorporated into the lamphouse. A lever type iris diaphragm is provided for aperture control.     Condenser    All microscopes come equipped with an ELWD (extra long working distance) condenser, N.A. 0.30, W.D. 73mm. Optional Condenser: N.A. 0.55, W.D. 20.5mm is available for more demanding work with 40X objectives.     Photo port    All models are equipped with a front mounted camera port suitable for CCD, 35mm, or digital cameras. Optional camera adapters are available to facilitate a wide range of camera and video support.     Body    Cast aluminum alloy body for rigidity and exceptional stability.