Darkfield illumination is an indispensable tool for inspection and machine vision applications. This is especially true when viewing clear or mostly clear parts for internal or surface features such as edges or defects that can be washed out using standard backlighting or brightfield front illumination.
Primarily, darkfield illumination gets its name from the fact that the background is dark, as opposed to the brightfield of a backlight. When the Darkfield Attachment is placed on the ring light it creates a cone of light that diverges from the optical axis. Perfectly clear, stress-free objects exhibit no image. Edges, features and dust, on the other hand, redirect light toward the optical axis and register in high contrast to the rest of the field.
The darkfield attachment can only be used with ring light #54-173. The attachment conveniently snaps onto either ring light guide easily using a rubber O-Ring. This replaces the hassle of set screws and allows the Darkfield Attachment to be rotated. The window is held in place by a split ring rubber gasket and can be removed. The ring light guide requires a light guide adapter to attach to the illumination source. For proper contrast, our Light absorbing black out material is highly recommended.
Light absorbing black out material is also useful to ensure a pure black background. The black out material is available in various sizes and can be easily cut to size.
Note: Edmund Optics has lowered the prices of the Replacement Window #54-827 more than 30%! Supplies are limited! Prices shown reflect discount.