Tom, as a photographer you should understand the concept of focal points and focal lengths. If water droplets act as a lens on the surface of a leaf, the point at which the light converges to burn the leaf does not occur directly adjacent to the lens (aka leaf surface). The light convergence would occur some short distance beyond the face of the leaf. Its the same concept as using a magnifying glass to burn things. You don't hold the lens directly against the surface. This myth has been thoroughly disproved by researchers.
Tom, as a photographer you should understand the concept of focal points and focal lengths. If water droplets act as a lens on the surface of a leaf, the point at which the light converges to burn the leaf does not occur directly adjacent to the lens (aka leaf surface). The light convergence would occur some short distance beyond the face of the leaf. Its the same concept as using a magnifying glass to burn things. You don't hold the lens directly against the surface. This myth has been thoroughly disproved by researchers.