WHAT IS WORKING DISTANCE (WD)?
Working distance refers to the physical space between the front element of an objective lens and the sample surface when the sample is in focus. It defines the available space between the optical system and the measured object during operation.
KEY ASPECTS AND IMPORTANCE
Working distance directly affects sample accessibility and measurement flexibility. A longer WD provides more space for larger samples, steep geometries, tools, or additional instrumentation, while a shorter WD is typically associated with high-magnification and high-numerical-aperture (NA) objectives that require the lens to be positioned closer to the surface.
Selecting the appropriate working distance is important for balancing resolution, accessibility, and measurement reliability in applications such as microscopy, semiconductor inspection, and industrial metrology.
