Some years ago I read where someone suggested that in an emergency a lens from a pair of binoculars could be used to make a fire. A single convex lens is the preferred instrument for solar fire craft but I had to wonder if a fire could be generated without removing a lens from a binocular, but rather, if just focusing through the Binocular as-is would work so I set out to find out.

I soon found out that positioning a pair of binoculars to align with the sun can be somewhat challenging. The focus is small but not as small or intense as a single lens. I had focused initially on my had to get a sense of the heat generated but it was somewhat weak. As with all solar methods, using a dark tinder works best so I chose a piece of charcloth as my tinder upon which to focus.

I initially tried this method in late afternoon before sunset which in the final days of October is not optimal but was successful after much patience. I would guess that a noon-time effort would be more successful.

I usually carry a credit card sized fresnel magnifier in my wallet which is much easier and effective to start a fire just to use, especially in an emergency situation.