25mm F/0.51 參考球面 - 1/10 波長

Took this out of the box and the surface quality on the 1/10 wave sphere is visibly flawless under a bright lamp. It paired perfectly with my existing Fizeau interferometer setup for testing smaller optics.

The 4% reflectivity is exactly what I needed for my interferometry setup, and the 1/10 wave accuracy shows up in the data as a clean, steady reference. Took a bit of fiddling to align it initially, but once it's locked in, results are repeatable every time.

The mounting threads are perfectly machined, and the 1/10 wave accuracy gives me consistent results every time I test a lens. It's pricey, but for precision work this sphere is worth every penny.