كرة نقل 4 بوصة F/0.75 -- كرة فائقة 1/40 موجة

This F/0.75 sphere cleaned up the fringes on my 6-inch test part immediately—the 1/40 wave accuracy is exactly what I needed for final polishing verification.

The 1/40 wave PVr spec is no joke—my interferometer readings were clean and repeatable right out of the box. The F/0.75 aperture covers my 4-inch setup easily, and it feels solidly built for the price point.

Interferogram fringes stayed dead straight across the full 4-inch aperture, and the 1/40 wave PVr spec held up exactly as stated when I checked it on our test bench. The F/0.75 speed is brutal for alignment, but once set, the wavefront stayed stable even after an hour of warm-up.