32 Inch 4% Reference Flat

The 4% reflectivity is spot-on for my interferometer setup—the fringe contrast is perfect. It arrived well packaged and shows no visible surface defects under green light.

Finally, a reference flat that actually lives up to its 1/8 wave spec out of the box. The 4% reflectivity is perfect for my interferometer setup without needing extra coatings.

The 32-inch aperture is massive, yet the surface quality holds up beautifully across the whole clear area—I checked fringes edge-to-edge and saw no surprises. It arrived well-packed and the 4% reflectivity paired perfectly with my interferometer’s beam splitter setup.