Nikon DF/BF Microscope Filter Assembly ND32 Neutral Density Slider Darkfield

Nikon DF/BF Microscope Filter Assembly ND32 Neutral Density Slider Darkfield

This is a Nikon darkfield/brightfield (DF/BF) filter assembly equipped with an ND32 neutral density slider filter. The assembly mounts into a compatible Nikon upright microscope's filter turret or condenser stage and uses a simple push/pull slider mechanism to switch between brightfield (push) and darkfield (pull) illumination modes. The ND32 neutral density filter element reduces light intensity without altering color balance, allowing fine control over specimen illumination.

Specifications & What's Included

• Brand: Nikon
• Assembly type: DF/BF (Darkfield / Brightfield) filter module
• Included filter: ND32 neutral density slider filter
• Switching mechanism: Push/pull slider — push for brightfield (B.F.), pull for darkfield (D.F.)
• Filter elements: Two optical elements visible in slider — includes ND32 neutral density filter and a second coated filter element (green/violet anti-reflection coating visible)
• Housing: Circular white/grey filter housing with black anodized aluminum mounting bracket
• Mounting: Bracket-style mount compatible with Nikon upright microscope filter turret
• PUSH B.F. / PULL D.F. label present and legible on housing
• Filter assembly only — no additional accessories included

Applications

Darkfield and brightfield illumination are two of the most fundamental contrast techniques in optical microscopy. Brightfield illumination transmits light directly through the specimen and is the standard mode for most routine biological, histological, and materials examination work. Darkfield illumination blocks the central illuminating beam and uses only oblique light scattered by the specimen, making unstained transparent specimens — such as live cells, microorganisms, and fine surface features — appear bright against a dark background. The ability to switch between these two modes in a single assembly is particularly useful in research and quality control labs where specimens require rapid re-examination under different contrast conditions. The ND32 neutral density filter allows the operator to reduce lamp intensity by a fixed factor (approximately 1/32 the transmitted light) without affecting color temperature, which is especially important for photomicrography and camera-coupled imaging where precise exposure control is needed. This type of filter assembly is commonly used with Nikon upright biological and industrial microscopes and is a standard accessory for labs performing live-cell imaging, metallographic inspection, and general optical examination work.