When I was about 10-12 my dad had a concave mirror that believe came from a telescope of some sort. It was about 10” in diameter. He demonstrated that it worked much better as a death ray for green army men than a simple magnifying glass. It broke a few years later. I would like to purchase another one. But I don’t know what I should look for as far as getting one that will do what I want. The focal length, if that is the right term, was about a foot from the mirror if I recall. It was close enough to let you hold what you were melting/burning but also keep your hands out of the way of the mirror. I would like one about 10” in diameter also I think, it seemed like a good size. I am also not terribly rich. So where should I look (science supply store?) and what specs do I need to look for?
There’s one with some minor flaws available on eBay for $10. Sounds perfect for playing around with.
Item # 140046940755
The mirror in the Edmund solar energy lab looks to be about the right size, and it’s cheap!
At 8X the cost, their solar furnace is spiffier looking.
Lol. Disadvantages - Doesn’t work at night.
That’s okay I have a lunar furnace for nights.