It’s been a series of odd coincidences around here lately. First off, Nick was taking an order for one of the more exotic of Canon lenses, the 800mm f5.6, so we were talking about exotic lenses in general and the big giants, like the Sigma 200-500 f/2.8 (a piddling 34.6 lbs for over 2 feet of lens. It needs its own battery. No, really) and my favorite big honking lens of all time, the Canon 5200mm f14 (pictures and a copy of the brochure page here, here, and here). Supposedly it had a working range of 18-32 miles and came with spotting scopes. Nice. This sucker reports to have been a very pocketable 220 lbs and 75.6″ long. Now, a lens taller than most adult men might sound massive, but if you stop to do some quick math and figure out that a 5200mm lens should be around 17 feet long, you might not find 75.6″ so bad.

It was a mirror lens, using mirrors in addition to glass elements to ‘fold’ light inside the lens, by first sending it to the back of the lens, then back up to a small mirror in the middle of the front element, and then finally sending it back to the sensor.

Then, the day after that, Jody was surprised to hear new announcements for mirror lenses (which have no aperture controls, you get one fixed aperture and need ND filters past that).

Then, today, I was reviewing the current Sony instant rebates, and saw the 500mm f8 Reflex sitting down in our Sony lenses. Apparently, if you buy Sony Alpha cameras you’ll find yourself in the unique position of having an available autofocus mirror lens, giving a fieldof view equivalent to a lens three times longer than it actually is.

Will it rival that $11,000 Canon for quality? No, but hey, for under $700 bucks and for it’s tiny size (well, compared to optically formulated 500′s), it’s going to be hard to beat. Don’t forget on any Alpha other than the A900 you’ll have a 1.5x crop making it a 750mm lens which is only about 5″ long.