Warning! You won't be able to use the quotation basket until you enable cookies in your Web browser.
Warning! Your Web browser is no longer supported. Please upgrade to a modern browser.

Matching Coverglasses

The coverglass is an important component of the optical path and should therefore meet the same standards of optical quality as the objective. High-quality objectives can only deliver their full potential if the corrected immersion medium and coverglass are used.

Dry, water and glycerol objectives are extremely sensitive to deviations in coverglass thickness. Objectives with a correction collar can be used to correct these deviations.


for use with and without coverglass


for use without a coverglass


for use with a 0.17 mm coverglass (DIN/ISO)


for use with 1.8 mm quartz glass window on heating stages


for use with coverglasses of 0 - 2 mm thickness 

The available standard coverglass thicknesses are:

No. 1


No. 1.5


No. 1.5H

0.17mm +/-0.005mm

The coverglass type that is required for optimal results depends on the immersion medium and the numerical aperture (NA). Table 1 may be referred to as a general rule.

Table 1: Coverglasses and immersion liquids


Immersion mediumWith or without
Coverglass type

Coverglass type
1.5 H

AirNA < 0.30NA < 0.70NA > 0.70
WaterNA < 0.60NA < 0.90NA > 0.90
Immersion type G (glycerol)NA < 0.80NA < 1.10NA > 1.10
Immersion type N (Oil)NA < 0.90NA < 1.30-
Immersion type F (Oil)NA < 0.90NA < 1.30NA > 1.30