Bestform 雷射鏡片，N-BK7 光學玻璃*

I was a bit skeptical about how much difference a bestform lens would make, but the reduction in spherical aberration is immediately obvious when adjusting my alignment. The optical glass feels solid and well-made, and my beam spot is noticeably smaller and cleaner than with my old plano-convex lens

The N-BK7 glass on these is noticeably cleaner than the economy lenses I'd been using, and my beam spot tightened up right away. Spherical aberration was the bottleneck in my setup and these pretty much erased it.

Bought two of these to tighten up a diode beam and the spot size dropped noticeably compared to the plain plano-convex I had before. The N-BK7 glass is clean with no visible bubbles or sleeks, and the edges came nicely ground. Collimating at 650nm it holds a tight round dot even near full aperture.