B&H Photo has posted a longer review of Canon's legendary EF 1200mm f/5.6L. It's definitely a lens that presents some challenges when walking around New York City, but it still looks like a lot of fun.
Some History on the Lens:
Canon made this lens available by special order only. A $10,000 deposit was required with the order and manufacturing would only start when several lenses were put on order. Sports Illustrated magazine purchased two 1200mm lenses in the 1990’s. Canon lent a lens to the St. Louis Post-Dispatch in 1999, so they could document Major League Baseball slugger Mark McGuire’s single-season home-run record attempt from center field; photographing every pitch McGuire faced that season. The extreme focal length of the lens gives a unique perspective of the distant view from the outfield fence that other lenses cannot capture.
*The offer still stands, if you buy the lens, I'll buy you the LensCoat for it!