Cover glasses

Cover glass thickness affects the optical path between the specimen and the objective lens. Many microscope objectives are designed to perform optimally with a 0.17 mm cover glass. Using the correct thickness helps maintain image sharpness, contrast, and resolution, while deviations may introduce optical aberrations.

No. 1.5H is a classification for high-precision microscope cover glasses with a nominal thickness of 0.17 mm and a tightly controlled thickness tolerance. This specification ensures consistent optical performance and is commonly recommended for high-resolution microscopy.

High numerical aperture (NA) objectives are optically corrected for a 0.17 mm cover glass. Using a cover glass with the specified thickness minimizes spherical aberrations and allows the objective to achieve its designed resolution, contrast, and imaging performance.

The primary difference is the coverage area. The 18 × 18 mm cover glass is suitable for smaller specimens and is supplied in boxes of 1,000 pieces, while the 22 × 22 mm version covers a larger specimen area and is supplied in boxes of 200 pieces. Both products share the same optical specifications, including 0.17 mm thickness (No. 1.5H), controlled thickness tolerance, and a refractive index of 1.5255.