Last week my wife and I with our cousins visited the famous Monarch Grove in Pismo Beach State Park. This is the site where twice each year thousands of Monarch butterflies gather to mate, and to impress visitors with their beauty.
We used two Canon full-frame cameras: a 5D and a 6D, and we used a long, long combination of optics: a Canon 100-400 lens with two 2X telextenders attached to make the equivalent of a 1600mm lens! The maximum aperture was f11, but with a good tripod from Really Right Stuff, we were able to make some lovely portraits of Monarchs in the wild.