The black drop effect of 2012 Venus and 2016 Mercury transits.

Both images photographed with a Questar Q3.5 telescope. The Venus transit (in Hawaii) with a Nikon D700 camera and the Mercury transit (in Arizona) with a Nikon D800 camera. The Venus black drop was easily seen and even with a camera (D800) of 3X the resolution the Mercury back drop was still difficult.

Done