The AmScope B490 compound binocular microscope has a sliding head, a pair of 10x widefield eyepieces, a forward-facing nosepiece with four DIN achromatic objectives, Brightfield halogen illumination, a double-layer mechanical stage with a stage stop to protect slides and objectives from damage, and anti-mold surfaces to preserve optics in high-humidity areas. The compensation-free binocular viewing head has a pair of 10x widefield eyepieces and sliding head to adjust inter-pupillary distance, a fixed 30-degree vertical inclination to reduce eye and neck strain, and a 360-degree rotation capability to provide a more comprehensive view and enable sharing. The sliding head has a range of 55 to 75mm to accommodate individual eye differences, and bi-lateral dioptric adjustment accommodates individual eye-strength differences. The forward-facing nosepiece has 4x, 10x, 40xS (spring), and 100xS (spring, oil) DIN achromatic optical-glass objectives that combine with the eyepieces to provide color correction of magnified images. The 40xS objective is spring loaded to prevent slide damage when focusing. The 100xS spring-loaded oil objective 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 (transmitted, 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. Halogen illumination provides bright light in a concentrated path and has a rheostat to control light intensity. The 1.25 NA Abbe condenser is mounted on a rack-and-pinion control system, 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. The double-layer mechanical stage, with 1mm stage divisions, locks the slide into place and provides precise slide manipulation along the X- and Y-axis to allow coordinates to be recorded, enabling the viewer to return to a specific location on the slide. A stage stop prevents the stage from coming into contact with the slide and objectives. The stage is 5-1/2 x 5-1/2 inches (140 x 140mm) and has a traveling range of 2-15/16 x 1-3/4 inches (75 x 45mm). Graduated coaxial coarse and fine focus has a focusing range of 1-3/16" (30mm) and fine-focus divisions of 0.002mm (0.0000787") that enable measurements to be taken. Focus knob tension control prevents the stage from drifting out of focus. The solid-metal enamel-coated body is durable and resistant to stains and corrosion.

H is height, the vertical distance from the lowest to highest point; 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.

United Scope manufactures microscopy equipment and accessories under the brand name AmScope. The company, founded in 1996, is headquartered in Irvine, CA.

What's in the Box?

• AmScope B490 microscope with double-layer mechanical stage
• 10x widefield eyepieces, one pair
• 4x DIN achromatic objective
• 10x DIN achromatic objective
• 40xS DIN achromatic objective
• 100xS (oil) DIN achromatic objective
• Immersion oil, one bottle
• (2) Color filters; blue and green
• Spare halogen bulb
• Spare fuse
• Instructions