An easy visual guide
Microscope working distance explorer
How much room is there between the lens and your sample?
Working distance is the small space in front of an objective when the sample is in focus. Choose a microscope setup and specimen container to see what that space means. Enter the working distance printed in your objective’s specifications for a useful result.
Guide only: The examples illustrate possible setups; they cannot confirm that a particular objective, immersion medium and sample vessel are compatible. Check the manufacturer specifications and your microscope configuration before use.
Step 1 · Where is the lens?
Choose the microscope setup
An upright microscope commonly views slides from above. An inverted microscope often views cells through the bottom of a dish or flask.
Step 2 · The lens
Choose an objective
Air/dry describes the space between objective and specimen. Both covered and uncovered designs exist. Match the number engraved on your objective to the material in its optical path. Oil lenses need the specified oil at the lens; a special no-coverglass oil lens can exist, so check its inscription.
The coloured rings indicate objective magnification. LWD and ELWD mean long and extra-long working distance. These button values are examples only. Working distance varies greatly between objectives of the same magnification. These values are visual examples, not manufacturer specifications or compatibility approvals. Select a lens, then enter its actual working distance and check its coverslip correction and immersion medium on the objective datasheet.
Step 3 · The specimen
Choose what holds the sample
Examples only: on an upright slide this is the coverslip (or 0 if uncovered). An upright objective looking into an open vessel does not look through its bottom; the field starts at 0 unless you add a coverslip or another layer. In inverted viewing it is the slide or vessel bottom. Check the actual product thickness and objective correction. Rim heights are rough examples for the upright view and can be edited.
See the space
Lens, container and cells
Your working distance
8.00 mm
A useful amount of space
What does this mean for the image?
The number above describes space at focus. Image quality also depends on matching the objective’s coverglass marking and immersion medium to the sample. Many epi objectives are marked 0, but epi illumination alone does not prove that marking. Low-power exceptions may look usable despite a mismatch; check the actual lens.
Guide only. The working distance is specified by the objective maker under defined conditions, usually to the outer coverslip or vessel surface at focus. The displayed thicknesses and rim heights are editable examples, not universal specifications. Upright open-vessel viewing usually has no vessel bottom between lens and sample; inverted viewing looks through the bottom. A real sample may sit above it. Do not subtract the vessel bottom thickness directly from the stated working distance. Vessel shape, objective barrel width, stage and focus travel, immersion medium, coverglass correction and sample depth can change what is possible. Always confirm the objective and vessel specifications before bringing a lens close to a sample. Working distance explanation · Coverslip correction