消色差透鏡，光學皇冠玻璃與火石玻璃

Star testing showed pinpoint Airy disks with barely any color fringing on Jupiter, which is exactly what I hoped for from crown and flint glass. The polish is clean enough that I couldn't spot a single scratch under grazing light.

I swapped these into my astrophotography rig and the chromatic aberration on bright stars is basically gone across the whole field. The crown and flint glass pairing really does what it's supposed to, even wide open near the edges.

These lenses deliver diffraction-limited performance right across the full aperture, which I noticed immediately when doing a collimation test. Chromatic and spherical aberrations are both corrected so cleanly that my imaging setup needed zero tweaking, and the crown and flint pairing feels rock sol