Light microscopy

These images show the most commonly used type of light microscope, the compound, bright-field microscope. It is a compound microscope because it uses two lenses to form the final image. The lenses for light microscopy are made of glass. The image on the right shows the illumination pathway through the lenses of the microscope.

The illumination is white light produced by a lamp in the base.

The illumination is white light produced by a lamp in the base.

The slide is secured to the stage and the stage can be moved in the X and Y axes by the stage control knobs.

Focus is adjusted by coarse and fine controls.

For light microscopy, glass lenses focus the light and magnify the image.

After being reflected by a mirror, light from the base is focused on the slide by the substage condenser lens.

The objective lens collects the light immediately after it passes through the tissue section. It forms an initial image and provides magnification. Microscopes have multiple objective lenses, each with a set magnification, generally 4x, 10x, 40x and 100x. Different objective lenses can be selected by rotating the turret to which the lenses are attached.

After passing through the objective lens, light is reflected to the ocular lenses, which provide an additional 10x magnification of the image. The final magnification of the image is the product of the objective lens magnification times the ocular lens magnification. This bright-field microscope is an example of a compound microscope because it uses two glass lenses to form the final image.

From its source in the base, light is reflected upwards and concentrated by the substage condenser lens. The light passes through the tissue section mounted on a glass slide placed on the stage. The light then passes into the objective lens, after which is it reflected to ocular lens. The final magnification is the product of the two lens magnifications.

From its source in the base, light is reflected upwards and concentrated by the substage condenser lens. The light passes through the tissue section mounted on a glass slide placed on the stage. The light then passes into the objective lens, after which is it reflected to ocular lens. The final magnification is the product of the two lens magnifications.

From its source in the base, light is reflected upwards and concentrated by the substage condenser lens. The light passes through the tissue section mounted on a glass slide placed on the stage. The light then passes into the objective lens, after which is it reflected to ocular lens. The final magnification is the product of the two lens magnifications.

From its source in the base, light is reflected upwards and concentrated by the substage condenser lens. The light passes through the tissue section mounted on a glass slide placed on the stage. The light then passes into the objective lens, after which is it reflected to ocular lens. The final magnification is the product of the two lens magnifications.

From its source in the base, light is reflected upwards and concentrated by the substage condenser lens. The light passes through the tissue section mounted on a glass slide placed on the stage. The light then passes into the objective lens, after which is it reflected to ocular lens. The final magnification is the product of the two lens magnifications.

Carl Zeiss AG, Oberkochen, Germany