Microscope lenses and microscope objectives include eyepieces or oculars, optical filters, adapters or mounts, condensers, and other optical components for microscopy. There are many different types of optical lenses for microscopy. Choices include achromatic, condenser, eyepiece, wide field eyepiece, and semi-plan lenses. Achromatic lenses and semi-plan lenses are used to improve the alignment of colors at the focal point in order to provide a clearer image. They differ in terms of glass type, cost, and index of refraction. Condenser lenses are higher-power objective lenses that increase illumination and resolution. These microscope lenses and objectives have very small diameters and are mounted at or below the focusing or condenser stage. Eyepiece lenses are located at the top of the microscope and are available in 5X, 10X, 15X, and 20X designations. Wide field eyepieces have a larger diameter and a wider field of view.
Microscope lenses and microscope objectives are used with various types of optical filters. Color filters include a wide range of products that are distinguished by their specific color spectrums and wavelengths, as well as their Schott glass composition. Color filter glass, also known as Schott glass, is distinguished by its absorption of optical radiation, depending upon the color. Neutral density filters (gray filters) decrease the intensity of light without altering the relative spectral distribution of the energy. Associated with microscope lenses and objectives, these optical components filter the entire visible spectrum evenly, allowing light reduction without affecting color or contrast. Attenuation is accomplished by using either a light-absorbing glass or a thin-film metal coating that combines absorption and reflection. Specialty filters for microscope lenses and objective are also available.
Adapters or mounts, condensers, and other optical components are available from suppliers of microscope lenses and microscope objectives. Abbe condensers have an iris-type aperture to control the diameter of the light beam that enters the lens. C-mounts are adapters for video cameras. Typically, the user removes the camera lens and installs the C-mount, which connects to the microscope’s trinocular port. Unlike C-mounts, T-mounts are used with still cameras instead of video cameras. Other optical components for microscope lenses and objectives include contrast plates, cover slips, diaphragms, illuminators, mechanical stages, and mirrors. The objective lens is the microscope lens closes to the object.