Ultra Telephoto Lenses
When Canon pioneered the “DO” (Diffractive Optic) lenses we thought it future lenses are going to be lighter and longer telephotos would become a reality! Well, there is a compromise in quality compared to the traditional siblings. And the prices weren’t helping either.
Then when Nikon came out with the 200-400mm VR lens, there were rumors as to a 500-600 VR. Now that Nikon has VR in its big gun arsenal, the 500-600 may never see light. Then Canon comes out with a 800mm 5.6 IS.
So we did some scouting for long telephoto lenses. Guess what showed up! A Canon 5200mm mirror lens. Check this out…

It is supposed to be capable photographing objects 18 to 32 miles away.
More about it here:
http://www.canonfd.com/mirrorlenses/pages/page10.html
Here’s another one, the Canon 1200mm f/5.6 L lens:

It’s available for just $99,000 from B&H:
http://www.bhphotovideo.com/c/find/newsLetter/Mother-of-All-L-Lenses.jsp