The two climbers on the face of El Capitan in Yosemite National Park were barely visible with the naked eye.  As a matter of fact I found these two by using my telephoto lens as a telescope and scanning back and forth across the face of the mountain until I discovered them.  I have to admire men with this much strength and courage.  I used the Mamiya RZ67 with the Mamiya Sekor 500mm APO telephoto lens (tripod mounted and mirror-up) to expose this scene on Kodak Portra 400VC negative film.