An ultra wide lens used to capture a lot of the scene or in tight spaces.
 

This is a slot canyon in Valley of Fire State Park in Nevada. Having a fish eye lens came in very handy and allowed me to capture images I wouldn't have been able to with a longer focal length.

These lenses have a 180 degree view.

This image has made an appearance before. I sot it in Yosemite and loved how the lends could capture both ends of the curved road and how it accentuated the curve, making this look like an island.

The focal length is typically 8 - 15 mm
 

This is about as wide as it gets. This is a group of tree in the June Lake Loop in the Sierras. The fish eye lens is also a very reliable lens for creating star bursts.

Used in the early 1900's as a meteorology camera to study cloud formations. Mass production for creative use began in the 1960's.
 

Tilt up or down to get different effects
 

Tilting up, like I have done here with this hot air balloon in Lake Tahoe, will cause the curve to tilt up at the sides. Tilt down and the sides will also point down.

Keep straight to use as a wide angle
 

This is Pigeon Point Lighthouse in Pescadaro, California. A wide angle lens is necessary to capture the lighthouse and surrounding landscape. In this case, I kept my lens centered to take advantage of the wide angle without the heavy distortion.

Get close, really close
 

This Pontiac was making an appearance at Hot August Nights in Reno, Nevada. I was a few inches away from this grill. The lens will let you get so close that you need to make sure you don't bump into your subject!

Anything placed in the center of the frame will be minimized, where placement on the edges will accentuate the subject.
 

This is Ashford Mill Ruins in Death Valley. It's a really cool place to shoot. On this morning, I thought it would be fun to capture it slightly different than usual and I like how the lens bends objects that you must be straight.

Intentional distortion

This is a shot from that hot air balloon above, shooting down on the Taylor Creek area in Lake Tahoe. I had a great time bending the lake by aiming down.

Replacement for a wide angle
 

This is a cave at Davenport Beach that you can actually get inside at low tide. It would be impossible to capture the entire thing without a super wide angle lens. By titling upwards, I have bent the ocean slightly too.

Accentuate rounded shapes and objects
 

This is Horseshow Bend in Arizona. The river forms a dramatic oxbow bend here, appearing almost as a full circle. In order to capture this, you must lay down on the edge and extend your shoulders and arms out. You must also have a super wide angle lens. This is where a fish eye lens comes in really handy.

This was actually just a scouting shot because I knew I would not be able to be here in good light. I wanted to know if I could actually do the required leaning over the edge. I managed to accomplish it without falling to death but I was so anxious that I had to wrap my lens strap around my wrists because my hands were sweating so bad!

Sky shots
 

This is a field of poppies near Spenceville, California. The lens allowed me to get really low and close so I could show the orange poppies against the blue sky.

Creative shots
 

This is the tail of an airplane I shot out at the Sacramento Airshow. I love how the circle at the bottom stands out with the lens distortion. I was so close, my head was touching the plane (don't tell the owner.)