4인치 F/1.5 울트라 구면 – 1/40 파

Took delivery of the 4" F/1.5 sphere for our optical shop and the 1/40 wave spec is no joke—the fringes are dead straight across the full aperture. Took a bit of fiddling to get the mount aligned, but once it's set, it's rock solid. That 15.8 nm PVr figure is honestly conservative.

Swapped this 4" F/1.5 sphere into our interferometer setup and the fringe quality is noticeably cleaner than our old one. The 1/40 wave surface figure holds up across the full clear aperture. Arrived well packed, no scratches on the coating.

The 1/40 wave spec is real—we're seeing fringe straightness that matches the certificate, no surprises. It's a pricey accessory, but for F/1.5 testing at this aperture, the surface quality holds up under repeated setups.