Reddit reviews Top Spinning Base, 3" (75mm) Surface - Double Concave - Optical Glass Lens, 200mm Focal Length - Optically True - Ground, Beveled Edges - Eisco Labs
We found 1 Reddit comments about Top Spinning Base, 3" (75mm) Surface - Double Concave - Optical Glass Lens, 200mm Focal Length - Optically True - Ground, Beveled Edges - Eisco Labs. Here are the top ones, ranked by their Reddit score.
DOUBLE CONCAVE || Highly polished, double concave lensSPHERICAL || Lens measures 3" (75mm) in diameter and approximately 12mm thick200MM FOCAL LENGTH || Diverging lens with a 200mm focal lengthOPTICALLY WORKED GLASS || Made of high quality, optically worked glass. Highly polished with beveled, ground edgesGREAT FOR PHYSICS CLASSROOMS or TOP SPINNING || This optically true lens is excellent for physics classroom demonstrations in optics and light refraction. It's smooth, concave surface also makes this lens ideal for top spinning
Their super cheap on Amazon
I'd like a larger one myself. Maybe double this size. But it works really well. My best time is around 14 minutes on this surface untreated. If that helps at all. Enjoy it man. I love mine.
Edit: Here is a pic for size comparison. I don't know why I'm telling you all this. I guess I would've wanted to know when I was looking around.