5. Canon 50mm f/0.95 Lens for Rangefinder 7

At an aperture of f/0.95, Canon claims this lens is 4 times faster than the human eye. Released in 1961 as a standard lens for the Canon 7 Rangefinder camera, there aren't many of these beauties left. Though it is attainable if you  are eBay diligent and are ready to lay down some cash. See a modern review of this lens here.

PRICE: ~ $2,300 USD

2. Sigma 200-500mm f/2.8 APO EX DG Ultra-Telephoto Zoom

No this is not the Hubble Telescope with a pea green paint job. It's the Ultra-Telephoto Sigma 200-500mm F/2.8 APO EX DG. This lens weighs in at just under 35 lbs (15,700 grams) with an incredibly rare aperture of f/2.8 at 500mm. Complete with a doubler for a focal range of 1000mm at f/5.6, Sigma recommends this lens for Travel, Wildlife, Sports & Action. This is probably the most readily available lens on this list if you can find it.

PRICE: $25,999 USD

3. Samyang 1,000,000th Lens Celebration - Gold Series Lenses

Good luck getting one of these 1983 Gold Series Lenses. They reside behind glass in the lobby of the Samyang Optics factory in South Korea. Some say they were made as gifts for select distributors, and others say they the set was made in celebration of the 1,000,000th lens produced by Samyang. Either way this is what dreams are made of.

PRICE: NOT FOR SALE

2.Nikkor 6mm f/2.8 Fisheye Lens

Introduced in 1972 originally developed for scientific and surveillance purposes, the Nikkor 6mm f/2.8 Fisheye Lens has a 220 degree field of view, enabling it to actually see behind itself. Here's a lovely note from page 6 of the original user manual:

"Be careful in the picture not to include unwanted objects such as legs of the tripod or the hands or feet of the photographer."

PRICE: ~ $95,000 USD

1. Carl Zeiss Planar 50mm f/0.75

This lens' roots go all the way back to 1874 with the first drafting of a double gauss lens (two back to back gauss lenses - like parentheses) . Kodak worked on a lens using this concept in 1938, then in 1941 during World War II, the Nazi's finally perfected the concept producing a 70mm f/1.0 to help aid in guiding night weaponry. In 1966 NASA refined the plans with the help of German optics manufacturing company, Carl Zeiss. Zeiss produced ten 50mm f/0.75 lenses, keeping one and selling 6 to NASA. American film director Stanley Kubrick got his hands on the other three for his 1975 film Barry Lyndon shot entirely by candlelight. Don't expect to see this on B and H Photo any time soon.

PRICE: NOT FOR SALE