So I pulled a fresnal lens from a big screen I need our garage I watched videos of people burning through metals. The most I've done is turn some wood black no flame and melt some plastic I can't get it positioned right. I know you want the light to be basically a small circle and bright but I've done this and it just doesn't get that hot. What am I doing wrong?
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How to position a Fresnal lens to get the hottest solar temperature?