Nice lens you got there is it a linear or spot lens? If its a linear you can sand and polish the linear lines off the back side and make it into a hi-powered spot lens that will metal rock, glass and metal. I got a 48 incher that was once a linear and converted it to a spot lens. Visit my channel and click on my Fresnel lens playlist
![Lp. Сердце Вселенной #1 НАЧАЛО ПУТЕШЕСТВИЯ [Новый сезон] • Майнкрафт](http://i.ytimg.com/vi/380Q7gLWGvk/mqdefault.jpg)
Nice lens you got there is it a linear or spot lens? If its a linear you can sand and polish the linear lines off the back side and make it into a hi-powered spot lens that will metal rock, glass and metal. I got a 48 incher that was once a linear and converted it to a spot lens. Visit my channel and click on my Fresnel lens playlist
Its a convex lens