非球面透鏡，光學皇冠玻璃

The aspheric surface dramatically reduced spherical aberration in my simple telescope build. Even with just a single element, the image stays sharp across most of the field. For the price of quality optical crown glass, you can't argue with the performance.

I used this to replace a spherical singlet in a small telescope build, and the difference in edge sharpness was obvious right away. The aspheric surface really does cut down the spherical aberration I was fighting before. Glass arrived clean with no chips or sleeks.

The single-element aspheric curve on this crown glass lens is beautifully polished, and it keeps my test