Review on 🔬 Enhance Science Education with Eisco Double Concave Diameter Length by Neil Bodell

I only bought this lens to build a spinning top spinning center and compared to a cheap makeup mirror I bought at my local grocery store, this lens doesn't work. The shooting time is literally half that of shooting on a vanity mirror. I suspect two things: the radius of curvature of the lens and the crappy surface finish of the lens. I haven't determined yet if the shape (curvature) of the lens is as advertised but I can clearly see the surface was rough and then they sped up the polishing process. This left the surface with a slight but visually observable "pebbly/pitted" appearance. I suspect these small bumps interfere with the rotation of the top and add friction, reducing spin time.