National Optical 161-ASC Dual-View Monocular Compound Microscope, WF10x Eyepieces, High-Contrast Objectives, 40x-1000x Magnification, Brightfield, Halogen Illumination, Abbe Condenser, Iris Diaphragm, Mechanical Stage, 110V

The National Optical 161-ASC Dual-View Monocular Compound Microscope has two 10x widefield eyepieces (one with pointer), a reverse-mounted nosepiece with four DIN high-contrast objectives that are parcentered and parfocal, halogen illumination, nested coarse and fine focus, a 1.25 NA Abbe condenser with iris diaphragm, and a mechanical stage. The dual-view monocular viewing head has two eyepieces for simultaneous independent viewing—one vertical and one with a fixed inclination to reduce eye and neck strain—and 360-degree rotation capability to provide a more comprehensive view. The vertical eyepiece can be used by a second viewer, can accept a camera mount (C-mount accessory sold separately), and has diopter adjustment to accommodate individual eye-strength. An eyepiece pointer is used to identify features for students. A reverse-mounted nosepiece keeps objectives out of the way to prevent damage and contamination, and to enable more secure slide handling. High-contrast objectives provide sharp color distinction. Parcentered and parfocal objectives ensure that the image stays centered and focused when the magnification is changed. The 40xR and 100xR objectives are retractable and spring loaded to prevent damage to the slide or objective when focusing. The 100xR objective is also an oil objective that provides increased resolution over a standard objective. A compound microscope is used for inspection and dissection of specimens when two-dimensional images are desired.

The microscope has lower (diascopic) Brightfield illumination that transmits light up through the specimen for enhanced visibility of translucent and transparent objects. Brightfield (BF) illumination allows the specimen to absorb light, resulting in a dark image on a light background. The halogen light source provides bright light in a concentrated path, and a rheostat controls the amount of light emanating from the lamp. The Abbe condenser can be adjusted to control the distance of the light from the stage and has an iris diaphragm to optimize the amount of light illuminating the specimen. Blue, green, and yellow filters are included to help naturalize the light when viewing various samples. The mechanical stage locks the slide into place and provides precise slide manipulation along the X- and Y-axes. Coaxial coarse and fine focus knobs are nested to speed focusing for left-and right-handed viewers. A stage stop prevents the stage or specimen from coming into contact with the objectives, and a focus tension control prevents stage drift. The cast aluminum frame provides durability and has a gray enamel finish.

W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.

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 161-ASC Dual-View Monocular Compound Microscope
• WF10x eyepiece, 18mm
• WF10x eyepiece with pointer, 18mm
• 4x DIN high-contrast objective
• 10x DIN high-contrast objective
• 40xR (retractable) DIN high-contrast objective
• 100xR (retractable) DIN high-contrast objective
• Neutral filter, 45mm
• Blue filter, 32mm
• Yellow filter, 32mm
• Green filter, 32mm
• (2) rubber eyeshields
• Hex wrench
• Dust cover
• Instructions