The National Optical 420T-430PHF-10 Trinocular Stereo Zoom Microscope has a pair of 10x widefield eyepieces, a trinocular port, a 1x to 4x zoom objective for 10x to 40x continuous magnification, upper halogen and lower fluorescent illumination, coaxial focus, and a fixed stage with clips. The trinocular viewing head has a binocular head with a pair of eyepieces with interpupillary adjustment, fixed inclination to reduce eye and neck strain, and 360-degree rotation capability to provide a more comprehensive view and enable sharing; and a trinocular port that accepts a camera adapter (sold separately). Dioptric adjustment accommodates individual eye-strength differences. The zoom objective provides low magnification and a longer focal length for inspecting large-scale specimens, or specimens that require hands-on manipulation or repair, including rocks, minerals, watches, or circuit boards. A stereo zoom microscope is used for inspection and dissection of specimens when three-dimensional images are desired, and provides zoom, sometimes called pancratic, magnification that allows the user to zoom in on the specimen within a continuous magnification range.

The microscope has upper (episcopic) illumination that reflects light off the specimen for enhanced visibility of opaque specimens and lower (diascopic) illumination that transmits light up through the specimen for enhanced visibility of translucent and transparent objects. The upper halogen light source provides bright light in a concentrated path, and a rheostat controls the amount of light emanating from the lamp. The lower fluorescent light source provides cool, white light for observing specimens as they would appear in their natural environment. Lighting can be configured for upper, lower, or simultaneous upper and lower illumination. The reversible black and white stage plate is used with top-mounted lighting to provide contrast with light- and dark-colored specimens. The frosted glass stage plate provides evenly diffused illumination. A blue filter helps naturalize the light. The fixed stage has stage clips to secure the slide or specimen in place while viewing. Coaxial focus eases focusing for left- and right-handed viewers. Focus tension control prevents stage drift, and a built-in slip clutch system prevents damage to the focus mechanism. The metal frame provides durability and has a gray enamel finish.

Microscopes are instruments used to enhance the resolution of an object or image. Types include compound, stereo, or digital. Compound microscopes use a compound optical system with an objective lens and an eyepiece. Stereo microscopes show object depth in a three-dimensional image. Digital microscopes are used to display an image on a monitor, rather than looking through a lens. Microscopes can have monocular (one), binocular (two), or trinocular (three) eyepieces, with varying magnification abilities. Magnification ability refers to the size of an image. Resolution, also known as resolvant power, refers to the clarity of the image. The interaction between field of view (FOV), numerical aperture (NA), and working distance (WD) determines resolution. Microscopes can control magnification through a fixed focus, or through a range of adjustments. They can also utilize LED, fluorescent, and mirror light sources to help control viewing capabilities. Microscopes are widely used in education, lab research, biology, metallurgy, engineering, chemistry, manufacturing, and in the medical, forensic science, and veterinary industries.

National Optical and Scientific Instruments manufactures microscopes and microscope cameras. The company, founded in 1991, is headquartered in Schertz, TX.

What’s in the Box?

• National Optical 420T-430PHF-10 Trinocular Stereo Zoom Microscope
• (2) 10x widefield eyepieces
• Reversible black/white stage plate, 80mm
• Frosted glass stage plate, 80mm
• Blue filter
• (2) rubber eyeshields
• Dust cover