Use cover glass with thickness No. 1.5H (170 nm High performance)

Modern high-performance microscope objectives are designed to be used with cover glasses of a thickness of 170 μm. The quality of the cover glass, in particular the compliance with the nominal thickness, has thereby a crucial impact on the imaging quality. Variations of thickness reduce the image contrast and result in image defects, most notably in spherical aberration. So, use high-precision cover glasses with thickness No. 1.5H with a thickness of 170 μm ± 5 μm. This new generation of cover glasses are highly recommended for objectives with high numerical aperture and high resolution, for example:

  • dry objectives: N.A. > 0.7
  • objectives for water immersion: N.A. > 1.0
  • objectives for glycerol immersion: N.A. > 1.2
  • objectives for oil immersion: N.A. > 1.3

For lower N.A. no. 1.5 with a thickness of 170 μm ± 5 μm is OK.  Most lenses on the Leica TCS SP-8 confocal microscope have a high N.A. so the use of no. 1.5H. cover glass is recommended. (Costs about 20 euro cents per cover glass).

No. 1.5:  Fisher scientific; order number: 360316

N0. 1.5H: Marienfeld