The Mitutoyo 378 Series objectives are suited for bright/dark field observation for inspection of scratches and imperfections on a surface, as well as concavity and convexity on a surface.

The Mitutoyo BD Plan Apo objectives have the world’s longest working distance and are infinity corrected for excellent clearance between the lens surface and the workpiece surface. These objectives provide flexible observation at high magnifications and independent correction of chromatic aberration.
• The BD Plan Apo objectives are available in long work distance, super long work distance and high resolution
• Long working distance makes it possible to observe workpieces that are usually hard to focus because of multiple feature heights
• Bright/dark field is ideal to inspect pieces for scratches, concavity and convexity on a surface
• The metallurgical plan apochromatic (M Plan Apo) objective provides a flat, chromatic aberration-free image throughout the field of view
• The mounting screw threads of objectives are M40 x 36TPI and conform to JIS B-7141-1988
• Magnifications are available in 2x, 5x, 7.5x, 10x, 20x, 50x and 100x