The AmScope B490ALED compound binocular microscope has a sliding head, interchangeable pairs of 10x widefield and 16x widefield eyepieces, a forwardfacing nosepiece with four DIN achromatic objectives, Brightfield LED illumination, a doublelayer mechanical stage with a stage stop to protect slides and objectives from damage, and antimold surfaces to preserve optics in highhumidity areas. The compensationfree binocular viewing head has interchangeable pairs of 10x widefield and 16x widefield eyepieces and sliding head to adjust interpupillary distance, a fixed 30degree vertical inclination to reduce eye and neck strain, and a 360degree 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 bilateral dioptric adjustment accommodates individual eyestrength differences. The forwardfacing nosepiece has 4x, 10x, 40xS (spring), and 100xS (spring, oil) DIN achromatic opticalglass 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 springloaded oil objective provides increased resolution over a standard objective. A compound microscope is used for inspection and dissection of specimens when twodimensional 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. LED illumination provides bright, cool light for working with temperaturesensitive or live specimens. The 1.25 NA Abbe condenser is mounted on a rackandpinion 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 doublelayer mechanical stage, with 1mm stage divisions, locks the slide into place and provides precise slide manipulation along the X and Yaxis 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 51/2 x 51/2 inches (140 x 140mm) and has a traveling range of 215/16 x 13/4 inches (75 x 45mm). Graduated coaxial coarse and fine focus has a focusing range of 13/16 (30mm) and finefocus 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 solidmetal enamelcoated body is durable and resistant to stains and corrosion. SpecificationsHeadCompound binocularEyepiecesWF10x, WF16xObjectives4X, 10x, 40xS, 100xS (oil)StageDoublelayer MechanicalLighting configurationTransmitted (lower)Condenser1.25 NA AbbeDiaphragmIrisLight sourceLED, 3WIllumination typeBrightfieldPower110VOverall dimensions12 x 9 x 16 inches (H x W x D)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 threedimensional 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 w