This is an upgraded B690-PL which includes a turret phase-contrast system for live-cell analysis among other things. Designed for professional biological applications, the microscope’s infinity-corrected optical system ensures reliable, low-distortion magnification, with plan-achromatic corrections for accurate colors, excellent field flatness and edge-to-edge sharpness. The halogen illumination system provides low-fatigue, evenly-distributed light for maximum contrast and definition. This model is a popular choice for veterinarians and university laboratories.

To customize the microscope to your viewing comfort, the eyepiece spacing can be easily adjusted using a precision Siedentopf mechanism. A diopter is available on the left ocular tube to compensate for asymmetry, and the ocular tubes are angled at 30° to comfortably accommodate a seated position without neck strain.

The objective turret provides instant access to 4 magnification levels to easily focus in on minute details from 40X to 1000X. This covers magnifications needed for studying hair follicles, cells, and bacteria. The turret’s reversed orientation provides more working room above the stage. These high-quality lenses are achromatically corrected to improve resolution and color accuracy, with planatic flat-field correction to provide edge-to-edge sharpness.

The large 2-layer mechanical stage provides smooth and precise movement for examination of specimen slides. The stage’s low-position controls are conveniently placed near the coaxial focus knobs for a streamlined workflow. Examining specimen slides is intuitive and precise for users at any skill level.

Built on Koehler illumination principals, the sub-stage lighting provides evenly-distributed light for optimal contrast. The halogen light-source provides bright illumination with a lower color-temperature for decreased fatigue when used for long periods. The Abbe light condenser has a high 1.25 numerical aperture for oil-immersion, and an iris diaphragm to optimize contrast and depth-of-field. The condenser holder uses rack-and-pinion height adjustment for precision control, and is centerable for proper alignment. The illuminator’s field lens provides an iris diaphragm to control light-spread, optimizing contrast and definition in specimen features.

A phase-contrast kit is included with a turret condenser and 4 plan-achromatic phase-contrast objective lenses. Phase contrast is used to reveal detail in indistinct objects, such as unstained cells and microorganisms that would otherwise appear invisible. By using a combination of specialized objective lenses and a modified light condenser, these invisible objects can be visualized by manipulating variations in phase. This turret condenser allows you to easily rotate through the four phase-contrast settings (4X, 10X, 40X, 100X). Each phase-contrast setting has a centerable annulus for proper alignment. Each of the phase-ring equipped objective lenses has plan-achromatic corrections for improved color and resolution, as well as edge-to-edge sharpness.